A powerful bomb blast has ripped through the central Pakistani province of Punjab, killing at least fifteen people, seven of them children.

The Monday explosion targeted the house of a local cleric, located on the outskirts of Mian Channu, about 90 kilometers (55 miles) east of Multan in Pakistan's most populous and politically important province, Punjab.

The death toll may further rise as most of the 70 people injured are said to be in a serious condition, the Press TV correspondent reported.

The Police suspect the explosives were placed inside the house, which was used to teach religious education to children.

Local TV stations also report that more than 150 homes in the neighborhood were partially or completely destroyed in the blast, with many people feared trapped under the rubble.

An investigation is under way into the cause of the blast.

President Asif Ali Zardari and Prime Minister Yusuf Raza Gilani have both condemned the attack, urging authorities to compile an immediate report of the accident.

The attacks come as hundreds of displaced Pakistanis begun their journey back home, two months after what the government describes as a massive anti-Taliban offensive in the country's northwest, forced them to flee their homes.

The refugees, who are mainly from the Jalozai camp in the North West Frontier Province, are however reluctant to go back to the Swat valley -- scene to Islamabad's recent "anti-militant" sweep -- following reports that the fighting is still going on in some areas of the region.

Reports also indicate that some refugees are refusing to return until they get compensation and ration cards.

This is while last week Gilani announced that it was time for displaced civilians to return home, claiming that the military operation in the Swat was over.

FF/DT