Photo: The Canadian Press

Pakistani police officers take positions following a suicide attack on a church in Quetta, Pakistan, Sunday, Dec. 17, 2017(AP Photo/Arshad Butt)

Two suicide bombers struck a church in Pakistani on Sunday, killing nine people and wounding more than 50 others, authorities said, in the first attack on a church claimed by the country's Islamic State group affiliate.

Hundreds of worshippers were attending services ahead of Christmas when the bombers appeared in the city of Quetta and clashed with security forces. One assailant was killed at the church entrance. The other made it inside, said Sarfaraz Bugti, home minister for the southwestern Baluchistan province.

Baluchistan Police Chief Moazzam Ansari praised the response of security forces guarding the church, saying the attacker who made it inside was wounded and unable to reach the main building.

"Otherwise the loss of lives could have been much higher," he told reporters.

Quetta Police Chief Abdur Razzaq Cheema said a search was underway for two suspected accomplices who escaped.

Local television showed ambulances and security patrols racing to the scene as women and children were being led out of the church's main gate.

The Islamic State group later claimed responsibility for the attack on their Aamaq news agency, saying two "plungers" from their group had stormed the church, without providing further details.

It was the first time the Islamic State group has claimed an attack on a church in Pakistan, though Muslim extremists have claimed church attacks in the past. 

Fifty-seven people were wounded in the latest attack, including seven who were listed in critical condition, according to Wasim Baig, a spokesman for Quetta's main hospital.