Suicide bombers have attacked an army post in Pakistan's northwest, killing 13 soldiers and 10 civilians, officials said, in an assault claimed by the Taliban.

At least 11 fighters were also reportedly killed in the attack on Saturday on a joint checkpost of the Pakistan army and a paramilitary force in the Sarai Norang area of Lakki Marwat district.

The raid on the army post began around 3:45am local time (22:45 on Friday GMT) and lasted for several hours, said

senior police officer Arif Khan Wazir. The fighters were armed with automatic weaponsand rocket-propelled grenades, he said.

Thirteen security forces personnel and 10 civilians, including three children, were killed in the attack, sources told Al Jazeera.

Another official said the civilians were killed when one of the suicide bombers ran into a house as security forces attempted to repel the attackers from the army post.

"A suicide bomber entered a nearby house in a residential colony of the irrigation department and blew himself up. Four children, three women and four men were killed there," Nisar Ahmed, a senior government official, told the AFP news agency.

"The explosion damaged four houses in the colony. Civilians who were killed in the attack were residents of these houses," he said.

'Revenge for drone strikes'

The Taliban disputed the claim that at least 11 fighters were killed, saying they had sent only four suicide bombers.

"We sent only four suicide bombers to attack this checkpost. We attacked it to avenge the killing of two of our friends in a recent drone strike," Ehsanullah Ehsan, a spokesman for Tehrik-e-Taliban Pakistan, told the AFP news agency.

"The Pakistan army and security forces provide assistance to the US for drone strikes. So, we are taking revenge for their cooperation with the US."

The attack followed a suicide bombing at a Shia mosque elsewhere in the northwest on Friday that killed 23 people and wounded more than 50, police said. It was the latest in a rising number of sectarian attacks in the country.

The Pakistani Taliban also claimed responsibility for Friday's mosque attack. The group has been waging a bloody war against the government for years and has carried out previous attacks on the country's minority Shia sect.