KABUL, Afghanistan — Taliban militants equipped with explosives vests and guns fought for a second day on Sunday in the southern city of Kandahar, targeting government and military compounds from commercial buildings.

It was the strongest offensive by the militants since U.S. special forces killed al Qaida leader Osama bin Laden in Abbottabad, Pakistan, last week.

The massive assault on the heavily protected city of Kandahar was believed to be a consequence of a jailbreak there last month, when 500 prisoners escaped through a tunnel from a high-security prison. Most of the escapees were Taliban fighters, and some were commanders.

Four insurgents who were arrested in the fighting on Saturday had fled the jail, Zemarai Bashari, a spokesman for the Afghan Interior Ministry, told reporters on Sunday in Kabul.

Residents of Kandahar had been afraid of attacks.

"The situation is very bad. There is fighting going on in the city. Those who escaped the jail last month have attacked the city," said one city resident, Nematullah Akbari. "My son has not been to school in the last two days."

Kandahar is also the name of the restive province in southern Afghanistan that lies on the border with Pakistan. It has been a hotspot of Taliban fighting against U.S.-led NATO troops and Afghan forces.

Four people, three of them military personnel and one a civilian, have been killed and around 40 have been injured, Toryalai Weesa, the provincial governor, told reporters.

Weesa said the fighting continued at a hotel where the insurgents were firing on the intelligence department.

Eleven of the militants were killed, seven of them detonated explosives and some were still hiding in the hotel, he said. They carried out 15 explosions, including four car bombings.

The provincial health director, Qayeum Pakhla, gave a higher toll. He told McClatchy in a telephone interview from Kandahar City that six people had been killed, four of them on Saturday and two on Sunday, and more than 50 had been injured.

Taliban spokesman Qari Yousuf Ahmadi said the militants killed 113 Afghan troops and three NATO soldiers since the attacks began on Saturday.

(Shukoor is a McClatchy special correspondent.)

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