At least eight people were killed and 30 wounded when two suicide bombers attacked a church in Pakistan during a service Sunday, just over a week before Christmas, police said.
Islamic State terrorists group has claimed the attack, the group's Amaq news agency said in an online statement. It said two Islamic State members had carried out the attack but provided no evidence for the claim.
Two women were among the dead at a Methodist church in the restive southwestern city of Quetta in Balochistan province, said provincial Home Secretary Akbar Harifal.
Several of the wounded were in serious condition, police added.
Officials said police intercepted and shot one bomber outside but the second attacker managed to reach the church's main door, where he blew himself up.
"Police were quick to react and stop the attackers from entering into the main hall," provincial police chief Moazzam Jah said.
Balochistan provincial home minister Sarfraz Bugti said around 250 people normally attend the church on Sundays, but the congregation had swelled to around 400 because it was close to Christmas.
"God forbid, if the terrorists had succeeded in their plans more than 400 precious lives would have been at stake," tweeted the home minister.
Liaqat Masih, a member of the congregation, said he was heartbroken by the violence and feared for his life as the firefight erupted between one attacker and police, who were later reinforced by paramilitaries and regular troops.
"I am devastated to see many of our dear ones dead and wounded today here in front of me," said Masih, 35.
Hours after the attack reports surfaced that a total of four attackers had been involved, with two escaping.
Senior police official Abdul Razzaq Cheema said investigators were analysing CCTV footage to check the claim and had launched a search for any further suspects.
Christians make up an estimated 1.6% of Pakistan's 200 million people and have long faced discrimination, sidelined into lowly paid jobs and sometimes the target of trumped-up blasphemy charges.
Along with other religious minorities, the community has also been hit by Islamic militants over the years.
Following the latest attack, dozens of Christians protested in the northwestern city of Peshawar and called on officials to protect religious minorities.
In 2013, 82 people were killed when suicide bombers targeted a church in the city.
And last year Lahore suffered one of Pakistan's deadliest attacks during the Easter season, a suicide bomb in a park that killed more than 70 people including many children.
The bombing was later claimed by the Jamaat ul Ahrar faction of the Pakistani Taliban.
Police and troops have been battling Islamist and nationalist insurgencies in mineral-rich Balochistan for more than a decade.