Maulana Fazlur Rehman, head of the Jamiat Ulema Islam party, told local TV after the attack in Charsadda town that he was unharmed but his vehicle was slightly damaged. The attack came a day after a suicide bomber blew himself up amid a crowd of Mr. Rehman’s supporters minutes after he passed by in a vehicle.

A roadside bomb struck a convoy carrying a prominent hard-line Islamist leader in north-western Pakistan on Thursday, killing 10 people in the second attack apparently targeting the politician in as many days, police said.

Maulana Fazlur Rehman, head of the Jamiat Ulema Islam party, told local TV after the attack in Charsadda town that he was unharmed but his vehicle was slightly damaged. The attack came a day after a suicide bomber blew himself up amid a crowd of Mr. Rehman’s supporters minutes after he passed by in a vehicle.

Mr. Rehman has been an outspoken supporter of the Afghan Taliban, but some militants in Pakistan have shown a willingness to target anyone connected to the U.S.—backed government. U.S. diplomatic cables released by WikiLeaks last year also revealed that Mr. Rehman allegedly sought support from U.S. officials in Pakistan despite his fierce criticism of Washington in public.

The 10 dead from Thursday’s attack included at least one policeman, said Rehman Gul, a police official in Charsadda. 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.

On Wednesday, a suicide bomber riding a motorcycle blew himself up at a police checkpoint that was surrounded by Mr. Rehman’s supporters who had showed up to greet him as he travelled to Charsadda to address a public gathering. The blast left Mr. Rehman unharmed but killed 13 others.

It was unclear at the time whether the bomber was targeting Mr. Rehman and his supporters, or if they just happened to be there when he hit the checkpoint. But Thursday’s attack indicated that Mr. Rehman was indeed being targeted.

No group has claimed responsibility for the bombings. Attacks targeting people like Mr. Rehman who have militant sympathies are unusual but not unheard of.

The most prominent militant sympathizer reportedly killed by insurgents was former Pakistani spy Sultan Amir Tarar - better known as Col. Imam - who helped the Taliban rise to power in Afghanistan in the 1990s.

The Pakistani Taliban said in February that they shot and killed Tarar after holding him captive for 10 months in northwest Pakistan because the government failed to meet their demands. The Pakistani Taliban has links to its Afghan brethren but is focused on fighting the Pakistani state.

The Pakistani government disputed the Taliban’s claims, saying Tarar died of a heart attack in January while in captivity.

About a year ago, a suicide bomber attacked a rally being held by the Jamat—e—Islami party, another Islamist group that is sympathetic to many of the goals of the Taliban and regularly criticizes army operations against them. The attack killed more than 20 police and civilians. Police speculated the target may have been officers watching over the rally.

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