KANDAHAR, Afghanistan (AFP) - - A desperate hunt was under way Saturday for more than 1,100 prisoners who escaped a jail in southern Afghanistan when Taliban rebels blasted it open, killing 15 guards, officials said.

The prisoners, some of them Taliban militants, fled when the rebels attacked the facility in the city of Kandahar late Friday, blasting it open with suicide bombs before shooting the guards.

The NATO force in Afghanistan said more than 1,100 prisoners were on the loose after what deputy justice minister Mohammad Qasim Hashimzai called the rebels' most sophisticated attack yet.

"A massive operation is under way to find the escaped inmates. The Afghan security forces are searching for them within the city and along the main and secondary roads," Hashimzai told AFP in the capital, Kabul. None has yet been caught, he added.

An AFP reporter based in the southern city said large numbers of security forces including those of the US-trained Afghan national army had been deployed to search vehicles.

A Taliban spokesman, Yousuf Ahmadi, calling AFP from an unknown location, said the rebels used suicide bombs and detonated a bomb-laden water tanker in the attack.

"First we exploded two suicide attacks and then our mujahedin (holy warriors) riding motorcycles entered the prison and killed the remaining security guards.

"We successfully freed all prisoners, including our jailed Taliban and other prisoners," he told AFP.

Authorities had so far recovered the bodies of at least 15 security guards, Ahmad Wali Karzai, the head of the Kandahar Provincial Council and a brother of President Hamid Karzai told AFP.

"We've discovered the bodies of 15 security guards who were killed in the attack. The casualties might be more," Karzai added.

"Several hundred prisoners including Taliban have escaped," he said, without giving a precise figure.

The Taliban have been battling Hamid Karzai's government since they were toppled from power in a US-led operation for failing to hand over Al-Qaeda chief Osama bin Laden in 2001.

The raid is a blow to the president, coming one day after world donors pledged 20 billion dollars to rebuild Afghanistan at a conference in Paris but also called on him to strengthen the rule of law.

Despite the presence of about 70,000 international troops mainly operating under NATO, the insurgency aimed at toppling the US-backed government in Kabul has gained pace in the past two years.

Most of the Taliban attacks include suicide and roadside bomb blasts as well as small-scale gunfights targeting security forces. But the Islamic rebels have launched some of their most sophisticated raids in recent months.

In January 2008 several Taliban militants wearing suicide vests raided a five-star hotel in the capital, Kabul, and killed eight people including three foreigners.

And on April 27, Taliban gunmen opened fire on a military parade attended by President Hamid Karzai, missing the President but killed three other people including an MP.