A pair of suicide bombers detonated themselves near two churches in the eastern Pakistani city of Lahore on Sunday as worshippers were gathered inside – killing 15 people, officials said, in the latest attack against religious minorities in the increasingly fractured country.

In the tense aftermath of the blasts, an angry Christian mob turned violent – blocking a major highway, burning cars, ransacking a bus terminal setting two people on fire who the mob suspected of involvement in the attacks. Christian demonstrators blocked roads in other major Pakistani cities as well.

The explosions occurred in quick succession in the Christian neighborhood of Youhanabad at two churches while parishioners were worshipping at Sunday morning services inside. The churches are about 600 meters (650 yards) apart.

At least 70 people were wounded, said Zahid Pervez, the provincial director general of health, who gave the death toll. Area hospitals were flooded with casualties and scenes of mourning. Shaheen Bibi’s 10-year-old son Abhishak was among those killed.

“My son had gone to the church to pray for a good result in his examinations,” Bibi said as she cried and struck her head against the chest of a relative. “He wanted me to sew him some new clothes if he passed his examinations.”

Life in Pakistan is increasingly dangerous for religious minorities, especially Christians. They have been targeted by extremist Sunni Muslim groups and are also discriminated against in the wider society, where they are often limited to menial jobs like garbage collection. Witnesses said the bombers targeted a crowded gate when a large group of worshippers was waiting to enter one of the churches.

“One bomber exploded himself near that gate, that created chaos and during the course of that, there was another blast,” one unidentified witness told Pakistan’s Geo television.

After the blasts, the mood among survivors quickly turned violent. Much of the country is already on edge after years of militant violence including an attack on a Peshawar school in December that killed 150 people – mostly students.

The angry crowd attacked two people they thought were connected to the attack, and, later, burned them to death while others attacked buses in the city, said deputy inspector general of police Haider Ashraf. Two police officers who were protecting the churches were also killed in the explosions, which Ashraf confirmed were caused by suicide bombers.

A spokesman for the Punjab provincial government, Zaeem Qadri, condemned the attacks but also said it was unfortunate that the mob had killed the two suspects rather than turning them over to police. He said authorities are reinforcing security at the 481 remaining churches across the city.

Extremist groupings appear to be targeting minorities more intensively recently, including attacks on a string of mosques belonging Shiite Muslims, a minority in Pakistan. In 2013, twin blasts at a church in Peshawar killed 85 people.

“There will be more of such attacks,” warned Ahsanullah Ahsan, a spokesman for the Pakistani Taliban, which claimed responsibility for the assault, in a statement emailed to reporters.

Prime Minister Nawaz Sharif has his power base in Lahore and his party, the Pakistan Muslim League-N, also runs the Punjab government, where his brother is chief minister. The provincial government has been accused in the past of not doing enough to protect religious minorities and fight extremist groups based in the province. SAPA