PESHAWAR - Pakistani villagers repelled an attack on an anti-Taliban mayor near Peshawar Sunday, police said, as the death toll from the latest suicide bombing to strike the under-siege city rose to 15.

The northwest capital on the fringes of a lawless tribal belt has been hit by four suicide bombings in a week, as Pakistani troops press on with a major offensive against Taliban fighters in their nearby mountain strongholds.

In Saturday's attack in Peshawar, a man detonated a cache of explosives as police tried to stop and search his car at a checkpoint.

"Four critically injured people including a child succumbed to their injuries in hospitals overnight," taking the death toll to 15, Peshawar district administration chief Sahibzada Anis told AFP.

Violence continued to plague the area Sunday, when about 50 militants with the banned Lashkar-e-Islam group set upon the home of Fahimuddin, a local mayor who had raised a militia to fight the Taliban.

Fahimuddin told AFP that some of his would-be assassins were disguised in the all-encompassing burqa garments worn by conservative women in Pakistan, and approached his home in Bazid Khel village on Peshawar's outskirts.

"There were around 50 attackers, three of them wearing burqas managed to reach near my house. My men stopped them and asked for identification but they started firing after flinging off the burqas," said Fahimuddin, who goes by one name only.

"It is 100 percent sure that these people came to kill me. They left behind grenades and Kalashnikovs," he said.

Karim Khan, a senior police official in Peshawar, confirmed the attack, and said three militants were killed in the ensuing clash. The rest fled the scene.

"The village militia repulsed the attack before the police reached the spot. The dead bodies of the three militants will soon be shifted to police headquarters," said Khan.

Lashkar-e-Islam (Army of Islam), which has loose ties to the feared Tehreek-e-Taliban Pakistan (TTP) movement, enforces prayers five times a day and punishes people accused of prostitution, gambling and other vices.

The TTP claimed responsibility for Saturday's suicide car bombing and a brazen attack on the Peshawar headquarters of the nation's top intelligence agency, the ISI, on Friday that killed 17 people.

The militia has vowed further attacks to avenge the assault on its South Waziristan stronghold, where 30,000 troops backed by fighter jets and helicopter gunships have been battling since mid-October to crush the Islamist threat.

Police spokesman Fazal Hayat said the authorities were filing a case against Lashkar-e-Islam head Mangal Bagh, blaming him for Saturday's attack.

Pakistan is pursuing multiple offensives against Islamist insurgents beginning with a spring assault in and around the Swat valley and moving against Lashkar-e-Islam in the Khyber area in September.

Their most ambitious offensive aims to crush the TTP leadership in South Waziristan, an operation which has the strong support of the United States, which fears Al-Qaeda operatives are also active in the tribal belt.

But a string of retaliatory attacks have struck Pakistan hard, with bombings hitting the northwest every week and killing more than 450 people -- most of them in Peshawar -- since early October.

Pakistan has also been dishing out weapons, money and ammunition to allied tribesmen and elders and encouraging them to raise militia against insurgents.

But pro-government groups are increasingly at risk, with the Taliban and other insurgents often targeting their leaders in bomb and gun attacks.

A suicide bombing last Sunday near Bazid Khel killed anti-Taliban mayor Abdul Malik and 13 others at a bustling livestock market.