DERA ISMAIL KHAN, Pakistan (AP) — A suicide car bomber killed at least eight Pakistani paramilitary troops Sunday in a region near the Afghan border that has been a target in a surge of suspected U.S. missile strikes.

The bomber rammed his vehicle into a checkpoint near the main gate of the Zalai Fort, exploding it as Frontier Corps troops gathered nearby, said Maj. Gen. Athar Abbas, the Pakistan army’s top spokesman. Four people were wounded, he said.

The fort is 12 miles outside Wana, the main town in South Waziristan, a tribal region considered a hub for al-Qaida and Taliban fighters involved in attacks on U.S. and NATO troops in Afghanistan.

South Waziristan was the site of one of two alleged U.S. missiles attacks Friday that killed 29 people, including several suspected foreign militants, intelligence officials said.

It was not immediately clear if Sunday’s suicide attack was linked to the missile strikes. However, the missile strikes have strained Pakistan’s alliance with the U.S. in its war on terror and spurred militant calls for revenge.

The Pakistani troops were washing their vehicles Sunday when the suicide attacker came, two intelligence officials said. They described the explosion as “large” and said it destroyed the checkpoint and damaged the front wall of the fort.

The intelligence officials spoke on condition of anonymity because they were not authorized to speak to media. It was not possible to immediately verify the details. South Waziristan is a dangerous, remote area where travel by foreigners and many journalists is restricted.

Under American pressure, Pakistan has deployed security forces throughout its northwest in an attempt to tamp down growing militancy. The troops have been frequent targets of attacks by militants, who have demanded Pakistan end its alliance with the United States.

Washington is suspected of launching at least 17 missile strikes of its own in northwestern Pakistan since August, an apparent reflection of U.S. frustration over Pakistan’s efforts against militants in its territory.

Pakistan routinely protests the missile attacks as violations of its sovereignty, but the strikes have continued nonetheless.

In a statement Sunday, Pakistani Prime Minister Yousuf Raza Gilani condemned the suicide attack in South Waziristan, saying he “deplored the loss of innocent lives.”