An apparent suicide bombing at a mosque in eastern Pakistan has killed at least 18 people and injured dozens of others. The deadly incident may be linked to the recent killing of a top-level terror suspect by Pakistani security forces.

The blast ripped through a house of worship in the city of Sialkot, close to Pakistan's border with India, while the building was filled with hundreds of people gathered for midday prayers.

The authorities suspect that a suicide bomber carried out the attack.

The mosque belongs to Pakistan's minority Shiite Muslim sect, and authorities in this majority Sunni Muslim country are attributing the attack to religious sectarianism.

Information Minister Sheikh Rashid Ahmed agreed, but told VOA the bombing may specifically have been to avenge the death of terrorist suspect Amjad Hussain, alias Amjad Farooqi, who was killed by Pakistani security forces during a shoot-out on Sunday.

"This [is] due to, maybe, [the fact] that we have killed a very important sectarian man," said Sheikh Rashid Ahmed. "Maybe they have given a reaction for this."

The dead man allegedly belonged to several Sunni extremist groups, and he was also a native of the region where Friday's bombing took place.

He was said to have been involved in two assassination attempts against Pakistan President Pervez Musharraf last year, and to have played a central role in the kidnap-murder of U.S. journalist Daniel Pearl in 2002.

Following the mosque bombing, hundreds of Shiite protesters converged on the site of the attack, chanting anti-government slogans and blaming the police for a lack of security. Some demonstrators pelted local police officers with rocks.

Sectarian attacks between Sunnis and Shiites are not unusual in Pakistan. At the end of May, a bomb was set off in a Shiite mosque in Karachi, killing more than a dozen people.