Two suspected suicide bombers were killed on Sunday when their bomb exploded prematurely near the residence of a former Pakistan government minister, police said.

The attackers were traveling by motorbike to target the residence of Ijaz ul Haq in Haroonabad, in the southern province of Punjab, when the bomb exploded, said local police chief Zafar Abbas Bokhari.

Haq, a senior leader of ruling Pakistan Muslim League-Quaid, was not at home when the explosion occurred.

It was the first suicide attack in Pakistan since opposition leader Benazir Bhutto died in a gun-suicide bombing attack on Thursday that also killed 22 other people.

Haq served as the minister for Religious Affairs and quit in November when the upper house of the parliament was dissolved ahead of parliamentary elections scheduled for January 8.

Islamic extremists groups blame Haq for playing a role in ordering military action last July against armed radical students of Islamabad's Red Mosque who were involved in a multi-week standoff with police.

According to the government, more than 100 students were killed in military action to end the seize, but their supporters claim between 3,000 to 5,000 male and female students died there.

Since the operation, Islamic militants have carried out a series of revenge attacks against security forces and government officials around the country. More than 500 people, including around 200 security personnel, have died in more than 35 such suicide attacks.

Two weeks ago, former Interior Minister Aftab Sherpao, who had oversaw the Red Mosque operation, survived a suicide bombing at a mosque packed with Muslim worshippers, missing him but killing but more than 50 people.