Jalalabad- Taliban fighters killed at least 11 people and wounded 22 in a suicide bomb attack and gunbattle at a police station in Afghanistan's eastern Jalalabad city early today morning, according to police and health officials.

The attack in one of Afghanistan's main cities comes ahead of a presidential election on April 5, and demonstrated the insurgents’ determination to disrupt the vote.

The assault began with two explosions just before dawn targeting the police station and a nearby square, close to compounds used by international organizations including the United Nations. The initial attack was carried out by two suicide bombers, one of them driving a three-wheeler vehicle.

The NATO-led force in Afghanistan sent helicopter gunships to support Afghan security forces as a fire fight raged for over three hours before they were able to clear the area of the remaining militants. Police said they shot dead six Taliban, and all of them wore suicide vests.

"From today's attack in Jalalabad so far, we have received 11 dead bodies and 22 wounded," said the head of the provincial hospital, Humayoun Zahir.

A police district chief was among the dead, according to Fazel Ahmad Shirzad, police chief for Nangahar province. The wounded included an Afghan assigned to a security detail for U.N. staff and the offices of a local radio and television broadcaster were also damaged in the attack, according to a security source.

The Taliban claimed responsibility in a text message sent to media. The militants have threatened to kill anyone participating in the election, and have stepped up attacks in heavily populated areas including the capital Kabul since the start of the year.

Security forces discovered at least two roadside bombs on the heavily guarded highway between Jalalabad and Kabul on Wednesday, and carried out controlled explosions.