His home is in Kabul's heavily guarded diplomatic enclave, and the attack came just a week after a 20-hour siege at the edge of the area sometimes known as the "green zone".

"Rabbani has been martyred," Mohammed Zahir, head of the Criminal Investigation Department of the Kabul Police, told Reuters. He had no further details.

Hashmatullah Stanikzai, spokesman for Kabul's police chief, said it was "probably" a suicide attack.

Copyright Reuters, 2011