Two suicide bombers attacked a Shiite mosque in eastern Afghanistan during Friday prayers, killing at least 29 people and wounding another 81, officials said.

Abdullah Asrat, spokesman for the governor of Paktia province, said the heavily armed attackers, disguised in the all-encompassing burkas worn by conservative Afghan women, opened fire on private security guards outside the mosque in the city of Gardez. Then they slipped inside and set off their explosives among around 100 worshippers.

Five of the seriously wounded were small children, he said.

No one immediately claimed responsibility for the attack, but the Islamic State affiliate in Afghanistan has targeted Shiite worshippers in the past. The group has also warned Afghanistan's minority Shiites that their houses of worship would be targeted.

Syed Sufi Gardezi, the most senior Shiite cleric in Gardez, put the death toll at 30. He described a scene of panic and distress outside the Imam-e-Zaman mosque as news of the explosion spread and relatives gathered.

Gardezi said the wounded were screaming for help and body parts of the dead were scattered throughout the single story mosque. The dead were all men and boys, he said.

Dr. Mohammad Wali Roshan, a physician at a local hospital, said some of the relatives, armed with sticks and guns, were furious at the lack of security and began beating people, even medical personnel who arrived to help the wounded.

"They were shouting that there was no security and screaming for their loved ones," he told The Associated Press in a telephone interview.

Gardezi blamed the Islamic State affiliate. He said the Taliban have a strong presence in the area but have never attacked Shiites in the past and have never threatened them.

Both the Taliban and the Islamic State group are made up of radical Sunni Muslims who want to overthrow the Western-backed government and impose a harsh form of Islamic law. But they are fiercely divided over leadership, ideology and tactics, and have clashed on a number of occasions. IS views Shiites as apostates deserving of death.

In the last two years, IS has attacked 24 Shiite cultural centers, mosques and schools, said Mohammad Jawad Ghawary, a member of the Shiite cleric council.

"In Afghanistan they are the biggest threat for Shiites," he said. He called on the Afghan government and the international community to do more to protect Shiites.