HERAT: Taliban militants stormed an Afghan court on Wednesday, killing at least 44 people in a bid to free insurgents standing trial, officials said, in the deadliest attack for more than a year.

It was not immediately clear whether the accused men had escaped the court complex in the western town of Farah, although a hospital doctor said one prisoner was among those being treated for injuries.

The multiple bomb and gun assault will raise further questions about the Afghans’ ability to secure the country as Nato winds down its combat mission in the war-torn country by the end of next year.

“I can confirm that 34 civilians, six army and four policemen have been killed and 91 people, the majority of them civilians, have been injured,” Najib Danish, interior ministry deputy spokesman, told AFP.

“Nine attackers have also been killed.”

The death toll was the highest in Afghanistan from a single attack since a Shia Muslim shrine was bombed in Kabul in December 2011, killing 80 people.

“The attack is over, but the casualties have unfortunately risen,” Farah provincial governor Mohammad Akram Khpalwak told AFP, putting the final death toll as high as 46.

“In total, 34 civilians and 12 (Afghan) security forces have been killed in the attack. We have also discovered the bodies of eight attackers, more than 100 people have also been injured.”

The governor added a group of Taliban had been brought for trial Wednesday, without giving further details.

Taliban militants fighting the US-backed central government claimed responsibility.

“Our fighters attacked several government buildings in Farah according to their planned tactic. They conducted the attack with small arms and grenades,” the group said on its website.

“The fighting happened after information that (President Hamid) Karzai's administration wanted to try several fighters in a cruel way in this court.”Taliban fighters frequently target government compounds equipped with suicide vests, rockets and machine-guns.

“At around 8:00 am (0330 GMT) five attackers riding in two military-style vehicles drove to the provincial court building, one (vehicle) detonated at the gate and three attackers entered the building,” Agha Noor Kentos, police chief of Farah, told AFP.

Wakil Ahmad, a doctor at Farah hospital, said medics were treating scores of wounded including two judges and one court prisoner.

Abdul Rahman Zhawandon, spokesman for the governor of Farah, said the area was sealed off as firing continued through the day and some attackers had also entered a Kabul Bank office attached to the court building.

The governor’s compound was around 200 metres away from the scene of attack, an AFP reporter said.

The Taliban insurgency has raged since a 2001 US-led invasion ousted their five-year regime from Kabul.

The militia has increasingly widened its attacks outside its main powerbases in the east and south, where Nato forces have focused their attention, to other areas such as Farah which borders Iran.

Nato combat troops are due to pull out of Afghanistan by the end of 2014, leaving responsibility for security to Afghan security forces, but there are fears that the violence will increase with their departure.

Last year gunmen dressed in Afghan police uniforms and wearing suicide vests stormed a government compound in Farah and killed seven people.

In November a roadside bomb planted by Taliban insurgents killed 17 civilians – mostly women and children – on their way to a wedding party in the province.