At least five people were killed and over 30 others injured after a hand grenade hit a religious procession in Pakistan's eastern Punjab province on Thursday, a government official said.

An assailant hurled a hand grenade at the Shia Muslims procession held to mark Ashura, the 10th day of Muharram, the first month in the Islamic calendar, in the busy neighborhood of Muhajir Colony in Bahawalnagar district of the province, Assistant Commissioner of Bahawalnagar Syed Usman Muneer Bukhari told Xinhua.

More than 400 people were present at the site when the blast took place, said the official, adding that security in the district has been beefed up following the blast.

The area has been sealed off and an emergency has been declared in the hospitals, according to local police.

The suspect who carried out the attack has been arrested by the law enforcement agencies, and has been moved to an undisclosed place for further investigation, police sources told Xinhua.