Billed as a symbol of peace between two faiths, a new place of worship has turned a poor suburb of Ankara into a battleground and exposed wider sectarian tensions within Turkey.
The project's blueprint envisages a Sunni mosque rising side by side with a new cemevi, or assembly house, to be used by Alevis, Turkey's biggest religious minority.
But with its concrete foundations barely set, Alevis suspect an attempt to assimilate their community into the Sunni Muslim majority and youths from the minority are battling riot police nightly.
In response, Ankara's mayor has dismissed the protesters as Assad's "soldiers" in an uncomfortable reminder of the largely sectarian civil war raging in neighbouring Syria.
Making up about 15-20 percent of Turkey's 76 million people, Alevis draw from Shi'a, Sufi and Anatolian folk traditions, practising distinct rituals which can put them at odds with their Sunni counterparts, many of whom accuse them of heresy.
Residents in Tuzlucayir, the poor and mainly Alevi suburb on the outskirts of Ankara, are determined to halt the project.
"We will not stop protesting until the construction stops," said Candas Turkyilmaz, a 29-year-old labourer from Tuzlucayir, pointing to construction workers busying around the site by day while riot police keep close watch from the hill above.
"Nobody knew what they were building at first. We thought it was just another mosque, but when we found out we started to protest. You cannot have a cemevi next to a mosque, our beliefs are different," said Turkyilmaz.
Even as the groundbreaking ceremony got under way this month, Alevis poured onto the streets of Tuzlucayir in protest. Since then mostly young Alevi men have fought nightly with police, drafted in to guard the mosque's construction site.
Hundreds of demonstrators, some armed with stones and slingshots, face off into the early hours with the riot police who fire tear gas and water cannon.
Broader demonstrations against Prime Minister Tayyip Erdogan this summer have resurfaced again in recent days, including in at least two Alevi districts of Istanbul. Protests have also erupted in Hatay province, an ethnic and religious melting pot right on the southern border with Syria.
The unrest, which intensified again following the death of a protester in Hatay's Antakya city last week, is still not on the scale seen in June and July, but appears to have adopted a more sectarian and violent tone.
In Tuzlucayir, tension is palpable even during the day. Smouldering barricades across roads have turned the suburb into a labyrinth, graffiti and slogans adorning its walls.
More than the concept itself, it is the patrons of the complex - a collaboration between the reclusive, U.S.-based Sunni preacher Fethullah Gulen and Izzettin Dogan, an Alevi elder in Turkey - that have aroused suspicion.
"Gulen wants to assimilate the Alevis, he wants to Sunnify us, and Izzettin Dogan could not set foot in this neighbourhood, he does not represent us," Turkyilmaz said.
Gulen - whose supporters say they number in the millions and are largely drawn from the same religiously minded professional class which helped to sweep Erdogan's Islamist-rooted AK Party to power in 2002 - has long loomed large over Turkey's constitutionally-secular state.
While sympathisers revere him as an enlightened, pro-Western face of progressive Islam, others see a more sinister agenda, suspecting his followers of infiltrating government and cultural institutions and exerting influence over organisations from the police and judiciary to the central bank and media.
Both he and Dogan have declared the complex a model for peace and rapprochement between the two faiths, following centuries of friction that persists today, and say they have backing from the wider Alevi community.
But last week 11 Alevi foundations in Turkey and abroad released a statement against the construction, rejecting it as a "project of assimilation". The entire youth branch of Dogan's CEM Foundation, one of many Alevi associations in Turkey, has also resigned in protest.
A prominent Alevi opposition lawmaker and folk singer, Sabahat Akkiraz, has organised a boycott of CEM Foundation's television and radio channels by several music production firms.
Tuzlucayir residents say those Alevi foundations that have backed the complex have ties to the government, and have mostly been formed in the past few years with scant members.
The government has tried to keep its distance, stressing that the project is not driven by the state. However, it has given more than tacit backing, sending its labour minister to release a symbolic dove at the groundbreaking.
Deputy Prime Minister Bulent Arinc has questioned whether the protesters really represent Alevis, saying the aim was to create the same harmony found in other Turkish cities where churches and mosques often sit in close proximity.
Ankara's AK Party Mayor, Melih Gokcek, known for his provocative comments on Twitter, made the tweet about Assad's "soldiers" over the weekend.
Alevis are often mistakenly grouped with Alawites, the sect to which Syrian President Bashar al-Assad belongs. Known locally as Arab Alevis, Turkish Alawites are based primarily in Hatay, where separate sectarian tensions have flared since Syria began descending into turmoil in March 2011.
While the communities have some similarities, Alawites in Turkey are people of Arab origin whereas Alevis are ethnic Turks or Kurds who mainly live in central Anatolia.
Long persecuted by the Sunni-dominated state in Turkey and the Ottoman Empire before that, many Alevis have chosen to assimilate, making their numbers hard to estimate, and the community has fallen victim to several massacres in history.
The government outraged Alevis this year when it named a planned third bridge over Istanbul's Bosphorus Strait after an Ottoman Sultan reviled by the community for slaying its ancestors in the 16th century.
The government is expected to announce soon details of its "democratisation package", a series of reforms largely meant to address the grievances of Turkey's ethnic Kurds and also Alevis, although many remain sceptical that the measures will be enough.
"The prime minister said he will announce soon what rights he will give to us Alevis. So how can he come into our neighbourhood and do this?" said one retired man in Tuzlucayir.
Indirect support for the project from the government has worried many Alevis, who say they would rather see the state meeting their community's long-standing demands.
"They should have asked us: 'do you need a mosque?' They have built three new mosques here but there was no need. They are empty, nobody comes in and out," said Mehmet Uzuner, head of the cemevi in Tuzlucayir, housed in a simple apartment block.
By residents' own estimates Tuzlucayir is around 90 percent Alevi. While the AK Party won almost 50 percent of the vote in the greater district of Mamak in the 2011 general election, it got less than 10 percent in Tuzlucayir.
At the heart of the Alevi demands is state recognition of cemevis as places of worship, which apart from increasing their rights would open the doors to state funding from the Religious Affairs Directorate, a body attached to the prime minister's office whose annual budget outstrips most ministries.
That demand has fallen on deaf ears. A row erupted last year when AK speaker of parliament Cemil Cicek said Alevism was a part of Islam and its place of worship the mosque, rejecting an opposition lawmaker's request for a cemevi to be opened in the parliament building.
At the Tuzlucayir community's cemevi, as elders recited a mystical song of love, or "deyis", Uzuner lamented the mosque he says has only brought unrest to his neighbourhood.
"I have headed this cemevi for 20 years and I have never seen our youth so troubled as in the past few days," he said.
"Will people go to this place if it is built? It is not possible," Uzuner said. "Then again, they will probably hand out free sweets and bicycles to the kids so there will be some. We won't stop them."