Pakistan ? A suicide bomber attacked the main border crossing for convoys ferrying supplies to U.S. and NATO troops in Afghanistan on Thursday, killing at least 19 security officers, officials said.

The strike will raise fears the Pakistani Taliban is regrouping and making good on its word to carry out revenge attacks following the slaying of its leader, Baitullah Mehsud, in a CIA missile strike earlier this month.

Also in the border region, two U.S. missiles hit a suspected militant compound, killing six people, the latest in a string of such attacks, intelligence officials said.

The suicide attacker walked up to a group of border guards outside their barracks at the Torkham checkpoint in the Khyber region and detonated his explosives, local police officer Sadiq Khan said. The victims were breaking their daylong fast during the Islamic holy month of Ramadan. The border had closed for the day a few hours earlier.