An explosion ripped through a busy intersection in southern Pakistan on Sunday, killing three people in an area that has avoided much of the Taliban-led violence that has plagued the country.

Authorities were investigating the nature of the blast, which occurred in Dadu city in southern Sindh province, said local police chief Ghazi Salahuddin.

The explosion damaged several buildings in the area, including a sweet shop that bore the brunt, said eye witness Ghulam Nabi Panwar.

"It was a huge blast, but it mainly destroyed the sweet shop and the rickshaw in front of the shop," said Panwar.

The explosion wounded nine people, who were brought along with the three dead to the main hospital in Dadu, said hospital official Rafiq Kolachi.

Pakistan has been wracked by a Taliban-led insurgency that has killed hundreds of people in the past few months. But attacks in Sindh outside the provincial capital of Karachi are relatively rare.