Jakarta - A group of Indonesian "cyber warriors" sit glued to screens, as they send out messages promoting a moderate form of Islam in the world's most populous Muslim-majority country.
Armed with laptops and smartphones, some 500 members of the Nahdlatul Ulama (NU) -- one of the world's biggest Muslim organisations -- are seeking to counter the Islamic State group's extremist messages.
"We'll never let Islam be hijacked by fools who embrace hate in their heart," tweeted Syafi' Ali, a prominent member of the NU's online army, a typical message to his tens of thousands of followers.
They are trying to hit back at IS's sophisticated Internet operations, which have been credited with attracting huge numbers from around the world to their cause.
Internet propaganda is believed to have played a key role in drawing some 500 Indonesians to the Middle East to join IS, particularly among those living in cities where it is easier to get online.
The dangers of the growing IS influence in Indonesia were starkly illustrated in January when militants linked to the jihadists launched a gun and suicide bombing attack in Jakarta, leaving four assailants and four civilians dead.
It was the first major attack in Indonesia for seven years, following a string of Islamic militant bombings in the early 2000s that killed hundreds.
- 'Wrestling with propaganda' -
As well as firing off tweets, the NU members have sought to dominate cyberspace by establishing websites promoting the group's moderate views, an Android app and web-based TV channels, whose broadcasts include sermons by moderate preachers.
The initiative has been building momentum for a while but started to pick up pace a few months ago. A handful of cyber warriors operate from a small office in Jakarta, while the rest work remotely, and the group mostly communicate with one another over the web.
But it will be an uphill battle and the NU, which has been promoting moderate Islam for decades, conceded they have previously struggled to take on IS's hate-filled messages.
"NU has for a while wrestled with this radical propaganda," said Yahya Cholil Staquf, secretary general of the NU, which claims at least 40 million followers.
"Every time we defeated them, it didn't take long for them to regain their strength."
The online drive comes as the NU is set to take its campaign to promote their tolerant form of Islam onto the international stage this week, with a two-day meeting from Monday of moderate religious leaders from around the world.
They aim to showcase their particular brand of the Muslim faith, known as "Islam Nusantara", to counter the IS jihadists' radical interpretation of Islam.
"Islam Nusantara", meaning "Islam of the Archipelago" -- Indonesia is the world's biggest with over 17,000 islands -- is accepting of diversity and stresses non-violence.
It grew up organically in Indonesia, as the religion entered the country gradually and had to mix with existing traditional beliefs such as praying at tombs, making it a naturally tolerant form of Islam.
Nowadays, most of the approximately 225 million Muslims in Indonesia practise a moderate form of Islam.
The NU wants to persuade Muslims from around the world to look for inspiration to Indonesia, where religious minorities and a multitude of ethnic groups mostly coexist harmoniously, rather than to harsher forms of Islam from the Middle East.
- Fight the rising tide -
The group nevertheless has a long way to go to fight the rising tide of IS propaganda.
Despite their good intentions, the NU cyber warriors appear amateur next to IS's well-funded set-up.
The jihadists, who control huge swathes of territory in Iraq and Syria, have a sophisticated online operation, using social media, apps and slickly produced videos.
They send about 200,000 tweets a day into the United States alone, according to US officials. It even has its own news agency, Amaq, which is often the first to report that IS is claiming responsibility for attacks.
In Indonesia, there are two main ways that IS propaganda spreads -- by supporters posting on websites and apps such as Whatsapp, Facebook, Twitter and Line, and through returnees from the Middle East preaching the group's radical ideology.
Most of the NU's online army are volunteers, often reaching into their own pockets to cover costs.
"ISIS has oil, while the only oil we have is for hair," Ali said, explaining the project's start was delayed for more than a year due to funding problems. Oil smuggling has been a key revenue source for IS.
Robi Sugara, a terrorism expert from NGO the Indonesian Muslim Crisis Center, welcomed the NU's online approach.
"It's a good strategy to make Google searches fill up with moderate Islamic content," he told AFP.
"The battleground for Islamic ideology has moved to the Internet, and by producing as many moderate websites as they can, they can keep more minds healthy."