Khost (Afghanistan): Five police officers were killed on Sunday after a team of suicide attackers armed with fire guns and disguised in police uniforms stormed a traffic police headquarters in east Afghanistan.

The attack in the restive Khost province, which borders Pakistan, came a day after six medical students were killed and 23 wounded when a suicide bomber struck at Kabul's heavily-guarded main military hospital.

Sunday’s attack started around 4:30 am and initially left three police dead, although sporadic gunfire continued for hours later.

Around nine hours later, Afghan and foreign forces stormed the building where four suicide attackers were holding out.

Provincial police Chief Abdul Hakim Ishaqzai said,”The resulting fighting killed another policeman and an Afghan soldier as three of the bombers detonated their explosives in the basement of the building.”

"The joint forces are still trying to kill or capture the fourth suicide attacker. The operation is still ongoing," he added.

A total of seven people have also been wounded in the attack, according to officials. This includes five police, one Afghan soldier and one civilian.

Deputy provincial police Chief Mohammad Yaqub said that four attackers forced their way into the building in the early hours while it was vacant except for the police guards and officers on duty.

Yaqub said that the attackers were dressed in border police uniform and were armed with vests and AK-47 rifles.

Although there was no immediate claim of responsibility for the latest incident, there has been a string of recent targeted, high-profile attacks in Afghanistan by Taliban who have managed to penetrate supposedly secure official premises.

Last month, three people died when an attacker got inside the Defence Ministry in Kabul and the police chief of Kandahar province was killed by his bodyguard.

Afghanistan's security forces are frequently targeted by the Taliban and other militants.

The Afghan police and army are to take on more responsibility for security as foreign combat troops withdraw in a process starting from July but not due to be completed until 2014.

There are currently around 130,000 international troops in Afghanistan.