KABUL: Taleban insurgents killed at least 20 people in a series of gun and suicide attacks in Afghanistan on Saturday, underlining worsening security as US-led NATO forces end their combat mission in the country.

A suicide blast wrecked an Afghan military bus in Kabul, killing seven soldiers, while a senior court official was assassinated in the city and 12 Afghan mine clearance workers were gunned down in the south. A senior Afghan defense official says that a suicide bomber struck a bus carrying Afghan Army personnel, killing six as violence in the country spikes just weeks before most international combat forces withdraw.

The Taleban claimed responsibility for the blast, which left the bus badly damaged as wounded victims were rushed to hospital.Maj. Gen. Afzal Aman, chief of operations at the Defense Ministry, says the Saturday afternoon attack in the southwestern suburbs of the capital Kabul also wounded 14, and that officers were among the dead. He added that the bus had been taking the officers home when it was struck, most likely by an attacker on foot.

The Taliban claimed responsibility for the attack, the third major incident of the day. In the morning, the head of the secretariat for the Afghan Supreme Court, Atiqullah Rawoofi, was gunned down outside his home in Kabul.

“A suicide attacker targeted an ANA (Afghan National Army) bus,” Defense Ministry spokesman Zahir Azimi said via Twitter. “(It) caused casualties. Numbers will be released later.”

A Kabul police spokesman said the suicide bomber had been on foot.

Military buses are regularly targeted by the Taleban.

On Thursday a suicide bomber killed six soldiers travelling on a bus in the Kabul suburbs.

Earlier Saturday, Taleban gunmen shot dead a senior Supreme Court official as he left his home.

A spike of attacks in recent weeks have heightened concern about stability as NATO readies to end its combat mission on Dec. 31 after a war that has failed to thwart the Taleban insurgency.

Other recent targets have included the French cultural centre, a female Afghan member of parliament, a British Embassy convoy and a three members of South African family killed when their compound was attacked.