PESHAWAR, Pakistan (AP) — Protesters in Pakistan’s restive northwest chanted anti-government slogans Friday as funeral prayers were held for 42 Shia Muslims who were ambushed and killed by gunmen a day earlier in one of the deadliest such attacks in the region in recent years.

The victims were traveling in a multi-vehicle convoy from the northwestern city of Parachinar in Peshawar, the capital of Khyber Pakhtunkhwa province, when the attack took place on Thursday. Six women were among those killed and 20 others were injured.

Survivors said the attackers got out of a vehicle and sprayed the buses and cars with bullets. No one claimed responsibility for the attack and police have not identified a motive.

Thursday’s attack took place in Kurram, an area dominated by Shiite Muslims. Sectarian clashes between the group and the majority of Sunni Muslims in Pakistan have killed dozens of people in recent months.

Tribal elder Jalal Bangash said bodies started arriving in the town on Thursday evening. Shia community group Anjuman Hussainia Parachinar has announced three days of mourning.

The coffins were draped in white cloth bearing red calligraphy. “Labbaik ya Hussein” was read, a Shia phrase commemorating the 7th-century martyrdom of the Prophet Muhammad’s grandson Hussein, which gave birth to their faith.

Locals carried the coffins up through Parachinar as people thronged the streets. Markets, shops, roads and schools were closed. Local residents and relatives of the victims staged a sit-in, demanding action against the perpetrators.

Ali Ghulam lost his grandson in the attack.

“He was a very innocent and noble man, only 40 years old and he left behind young children,” Ghulam said. “He worked to feed his children, he never fought with anyone. Now we are worried about his family and what we will do for them.”

Protests broke out in parts of the city, with people chanting anti-government slogans. Some people set fire to checkpoints and the gate at the entrance to the city. The elders asked for calm.

Shia Muslims make up about 15 percent of the 240 million people in majority-Sunni Pakistan, which has a history of sectarian animosity between communities.

Although the two groups generally live peacefully, tensions have existed for decades in some areas, particularly parts of Kurram.

Dozens of people on both sides have been killed since July, when a land dispute broke out in Kurram which later turned into general sectarian violence.