A Taliban suicide bomber wearing an Army uniform killed five foreign troops and four Afghan soldiers on Saturday in a brazen attack at the Afghan Army's Eastern headquarters.

It was the deadliest single incident in 2011 against foreign forces in war-torn Afghanistan and comes amid a wave of suicide attacks on security targets, three months before foreign forces start a limited pullback.

The latest strike was at an Army base in the Gambiri desert area in Laghman province, near Jalalabad city, the de facto capital of Afghanistan's East.

"Five International Security Assistance Force (ISAF) service members died following an insurgent attack in Eastern Afghanistan on Saturday," ISAF said in a statement.

ISAF spokesman Major Tim James confirmed that the deaths came in the attack on the Afghan Army base, but could not comment on the nationalities of those killed, in line with policy.

There were over 100 ISAF troops at the base, primarily tasked with mentoring the Afghan Army, James said.

Afghanistan's defence ministry said that four Afghan Army personnel were killed and eight people were wounded, including four translators.

Spokesman general Mohammad Zahir Azimi added that the ministry was investigating the possibility that the attacker was a member of the Afghan Army, rather than someone who had simply bought a uniform for the attack.

"We cannot totally rule out the possibility right away. It takes time to do some investigations," Azimi said.

A Taliban spokesman, Zabihullah Mujahid, claimed responsibility for the attack in a telephone call to AFP.

The blast came a day after the provincial police chief of Kandahar in Southern Afghanistan, Khan Mohammad Mujahid, was killed in a suicide bombing claimed by the Taliban in which his two bodyguards also died.

On Saturday's attack is thought to be the worst single attack against foreign forces since December, when six US troops were killed in a blast at an outpost in Kandahar province.

There has been a recent spike in suicide bombings — a key Taliban tactic — in Afghanistan, with authorities reporting nine in the last few days.

About 130,000 international troops are stationed in Afghanistan, two-thirds of them from the United States, battling the Taliban and other insurgents.

Limited foreign troop withdrawals from seven relatively peaceful areas of the country are due to start in July.

However, the significance of these withdrawals has been increasingly played down by Western officials who instead stress the key date for the country's security will be 2014, when foreign combat operations are due to end.

Afghan forces are set to take increasing responsibility for security as foreign troops pull back.

Local security personnel are frequently the target of attacks by the Taliban, who have been fighting an insurgency since 2001 when a US-led invasion ousted them from power.

US secretary of state Hillary Clinton warned at a Nato foreign ministers' meeting in Berlin on Thursday that nations involved in Afghanistan should not rush to the exit doors due to "political expediency and short-term thinking".

A total of 122 foreign troops have been killed in Afghanistan in 2011, according to the independent website iCasualties.Org.

That compares to 711 for the whole of 2010, the highest annual total since 2001.

The worst fighting in Afghanistan usually comes in spring and summer and the fighting season is starting to get under way.