* Taliban appear to be increasingly targeting civilians
* Second major attack on courts, employees in recent months
* Number of civilians killed, wounded rises year-on-year
A suspected Taliban suicide bomber in a car detonated a bomb close to minibuses taking Supreme Court staff home in the Afghan capital Kabul on Tuesday, killing at least 17 people and wounding almost 40, police said.
It was the second large-scale attack in Kabul claimed by the hardline Islamist group in two days. On Monday, seven insurgents, including suicide bombers, laid siege to Kabul's main airport for four hours before they were killed.
Tuesday's attack appeared to underline the Taliban's readiness to target civilians, particularly court officials, whom they consider an arm of the Western-backed government of President Hamid Karzai.
In April, Taliban gunmen killed 44 people in the main court compound in the western province of Farah. A Taliban spokesman said they had sent several warnings to court staff telling them not to work there.
Tuesday's bomb struck three minibuses ferrying Supreme Court staff home, Kabul police spokesman Hashmat Stanekzai said.
The attacker's car was parked on a road near the court compound and exploded when the minibuses passed, police said.
A Reuters witness described seeing a damaged minibus leaning at an angle against some trees about 30 metres from the point of the explosion. The witness later saw police carry two bodies from the same area.
The Supreme Court is less than 500 metres from the entrance to the heavily fortified U.S. embassy, and the bomb was heard across Kabul's diplomatic precinct, triggering numerous embassy alarms.
"We were sitting in a car when suddenly there was an explosion in the car behind me," Kabul resident Mira Jan, who was bleeding from a wound in the head, told Reuters.
The Taliban claimed responsibility for the attack in an email from spokesman Zabihullah Mujahid.
"The bomber in a car struck and killed up to 50 ruthless prosecutors and other workers," Mujahid said, adding that the bomber targeted four minibuses taking court employees home.
The Taliban routinely exaggerate the details and casualty tolls of their attacks.
The attack came on the same day that the United Nations' representative in Afghanistan, Jan Kubis, criticised the Taliban and other insurgent groups for being mostly to blame for the rise in civilian casualties in the first six months of the year.
The total of 3,092 civilians killed or wounded between January 1 and June 6 this year was 24 percent higher than the same period last year, Kubis said.