ISLAMABAD - Suspected U.S. missiles killed four people in the Pakistan's insurgent-dominated northwest Saturday, officials said. The strike is the latest in an escalating campaign targeting Taliban-linked militants near the Afghan border.

ISLAMABAD - Suspected U.S. missiles killed four people in the Pakistan's insurgent-dominated northwest Saturday, officials said.

The strike is the latest in an escalating campaign targeting Taliban-linked militants near the Afghan border.

Two intelligence officials said the missiles struck two houses Saturday in the village of Hurmaz in North Waziristan. A military official also confirmed the information. All three spoke on condition of anonymity because they were not authorized to speak to the press.

It was not clear who the four dead people were. North Waziristan is largely controlled by militants who launch attacks against NATO troops in neighboring Afghanistan.

President Barack Obama has ramped up missile attacks carried out by unmanned drone aircraft. Pakistan publicly criticizes the CIA-run drone program but some believe Islamabad secretly provides information for targeting.

Pakistan is itself fighting Taliban factions in several other northwestern regions, including an ongoing offensive in South Waziristan. However, the military has said it does not have the resources to immediately go into North Waziristan.

Pakistani airstrikes killed nine suspected insurgents Saturday in another tribal region near the Afghan border, an official said, bringing the total killed in a military offensive there to more than 100 this week. The fighting occurred in Orakzai, a tribal region where many Pakistani Taliban militants are believed to have fled to avoid an earlier army offensive in their main stronghold farther south.

The clashes illustrate a central difficulty of Islamabad's efforts to eliminate the Pakistani Taliban: As security forces clear out one area, the militants slip into other parts of a tribal belt where hide-outs are plentiful and the government presence is minimal.

The helicopter strikes Friday targeted several militant hide-outs while ground forces were clearing various areas in Orakzai, local official Sami Ullah said.

On Friday, officials said Taliban fighters seized a security checkpoint in the region, sparking clashes that killed five soldiers and 32 alleged insurgents. Security forces regained the site. Earlier in the week, airstrikes killed at least 61 suspected insurgents, officials said.

Many of the dead insurgents in the Orakzai tribal region were Arab and Uzbek, said Maj. Gen. Tariq Khan, the commander of the Frontier Corps, a major force in the battle against the Pakistani Taliban in the northwest.