JALALABAD  - A group of seven suicide bombers attacked a police base in the eastern Afghan city of Jalalabad on Tuesday, killing five officers, police said. One bomber set off a large explosion at the entrance of the quick reaction police headquarters before two bombers blew themselves up inside the facility and four others died in a gun fight with police.

“The first one detonated a car bomb; two others entered the base and detonated themselves and the remaining four were shot dead,” Hazrat Hussain Mashriqiwal, the Nangarhar province police spokesman, told AFP. The Taliban militants immediately claimed responsibility for the attack, claiming that it had targeted “foreigners and Israeli teachers” training Afghan police at the base in Jalalabad, the capital of Nangarhar. “There are heavy police casualties,” the group said.

Jalalabad is situated on the key route from the Pakistan border regions, where many militants are based, to the capital Kabul, and the city has been targeted by repeated suicide attacks in recent years. The last attack was on February 24 when a bomber rammed an explosives-laden car into the gates of the walled compound of the National Directorate of Security spy agency and detonated his bombs, killing two intelligence workers.

 Nine Taliban suicide attackers also targeted the Nato base at Jalalabad city airport in early December, killing five people and wounding several foreign troops. All the attackers in that assault were also killed, some blowing themselves up in two vehicles at the perimeter gate and others shot as they attempted to storm the base. It was the third attack on Jalalabad airport in 2012.

The Taliban have waged an 11-year insurgency against the Afghan government, which is backed by 100,000 Nato troops, since being overthrown in a US-led invasion for harbouring Al-Qaeda leader Osama bin Laden.

Afghan soldiers and police are taking over responsibility for the fight against the Taliban as international troops leave, but local forces are poorly-trained and fears are growing that Afghanistan could tip into further instability.