Pakistani security forces took control of a police academy in Lahore on Monday after militants rampaged through the complex, killing at least eight cadets and wounding scores before holing up inside for hours.

"The operation is over. Four terrorists were killed and three arrested," Interior Ministry Secretary Kamal Shah told Reuters. Shah said 89 policemen were wounded.

Punjab police chief Khawaja Khalid Farooq said at least eight recruits were killed though there had been reports the toll would be higher as there were 900 cadets in the academy at the time of the attack.

Three of the militants blew themselves up during the final assault, and commandos rescued 10 police being held hostage.

Television news channels showed jubilant police shouting praise to Allah, making victory signs with their hands, and firing in the air in celebration minutes after a fierce firefight inside the main academy building.

The latest brazen attack will heighten fears about mounting insecurity in nuclear-armed Pakistan. The assault came less than a month after gunmen attacked Sri Lanka's cricket team in Lahore, killing six police guards and a bus driver. Those gunmen escaped.

Islamist militants have launched a campaign of violence to destabilise the Muslim nation of 170 million people, and the one-year-old civilian government's ability to meet the challenge.

US President Barack Obama made support for President Asif Ali Zardari's government a centrepiece of a review of policy towards Afghanistan and Pakistan that was announced on Friday.

The principle objective of Obama's strategy is the annihilation of Al Qaeda in the two countries.

Salman Taseer, governor of Punjab province, said authorities had reports of four people confirmed killed, although television news channels put the number of dead at 20, including cadets.

One wounded policeman described how the attackers struck while police recruits were going through their regular morning drill on the parade ground in the eastern city.

"A grenade hit the platoon next to ours ... then there was continuous firing for about 20 minutes," the policeman told reporters gathered round his hospital bed.

"A man in light-coloured clothes -- I think they were white -- stood in front of us, firing at us. They wanted to do as much damage as possible."   

One witness told Reuters the gunmen attacked in groups of three or four from all sides.

Some eight to 10 militants attacked the recruits as they performed a regular drill on the parade ground at around 7:30 a.m (0230 GMT), and then went on to occupy the academy's main building.

Another wounded policeman recounted how he escaped when the gunmen burst into a room and began firing indiscriminately.

"I jumped from the second floor," he said. "There were dead bodies all over the place."    

Just before 4 pm, commandos launched an operation to retake the building, according to Major-General Shafqaat Ali, who described it as a joint operation by the army, paramilitary rangers and a crack police squad.

"Our forces stormed the top floor where they were holding positions," Major-General Ali said. "The operation is over the building is in our control."    

The siege had lasted nearly eight hours, with security forces firing from rooftops of nearby buildings, while gunmen returned fire and threw grenades, at one point forcing an armoured personnel carrier to retreat.

Before the siege ended, the police chief said one of the suspected attackers had been caught. Footage showed police kicking a bearded man on the ground before leading him through a throng of journalists.

Reports said the suspect was caught with a grenade in his possession and had an Afghan passport, though a cadet who fled the carnage said he heard the attackers speaking a dialect common to<