Dera Ghazi Khan, Pakistan - Angry protests have struck Pakistan's Punjab province after a bomb attack on a Shia religious procession on Thursday left 30 dead.
Dozens were also hurt in the suicide attack in the town of Dera Ghazi Khan.
As victims were buried in a mass ceremony, demonstrators blocked traffic for hours and attacked and destroyed police offices.
Sectarian tensions in south Punjab have recently been aggravated by the growing strength of Sunni Taleban militants.
Tension between Sunni and Shia extremists in Pakistan has existed for many years.
Police patrols
Schools, shops, businesses and offices were closed in Dera Ghazi Khan after a night of violent protests.
AAttacks on property continued into Friday morning but officials say the situation is now under control after reinforcements were called in.
Police spokesman Ausaf Ali Rana told Agence France-Presse news agency: "There are heavy police patrols. Most people are staying at home and police have deployed at Sunni mosques."
Earlier, a senior Punjab police official said the attack was definitely carried out by a suicide bomber "wearing a jacket packed with 12kg of explosives".
"We have recovered body parts and pieces of metal from the exact point of attack," deputy inspector general Athar Malik told reporters.
AFP also reported police as saying 16 suspects had been arrested in connection with the blast.
Local MP Mohsin Khan Leghari accused the provincial government of neglect.
"The Punjab government is too busy with politics to pay attention to the security of ordinary people," he said.
Shia worshippers were leaving a mosque when the bomb went off.
Television footage showed bodies surrounded by debris and ambulances, with survivors wailing and beating their heads in grief.
Southern Punjab is home to a number of violent sectarian groups with links to al-Qaeda and the Taleban.