Maulana Fazlur Rehman was unharmed in the attack but 10 people, including a policeman, were killed [AFP]

A roadside bomb has struck a convoy carrying a prominent Islamist leader in northwestern Pakistan, killing nine people, in the second attack apparently targeting the politician in as many days, police have said.

Maulana Fazlur Rehman, head of the Jamiat Ulema Islam party, told local TV after Thursday's attack that he was unharmed but his vehicle was slightly damaged.

The nine people killed included at least one policeman, said Rehman Gul, a police official in Charsadda town, where the attack occured.

The blast also wounded at least 20 people, he said.

Local TV footage showed a police truck damaged by the blast, its front partially ripped off and its side covered in shrapnel holes. Several nearby shops were also damaged and their goods spilled out into the street.

The attack came a day after a suicide bomber blew himself up amid a crowd of Rehman's supporters minutes after he passed by in a vehicle.

The blast left Rehman unharmed but killed 13 others.

Rehman has been an outspoken supporter of the Afghan Taliban, but some fighters in Pakistan have shown a willingness to target anyone connected to the US-backed government.

US diplomatic cables released by WikiLeaks last year also revealed that Rehman allegedly sought support from US officials in Pakistan despite his fierce criticism of Washington in public.

Source: Agencies