Intelligence officials say Pakistani fighter jets have bombed militant targets along the Afghan border, killing at least nine insurgents.

Pakistani officials said Wednesday's air force attacks on militant hideouts in the South Waziristan region come as troops continue to prepare for a broader ground operation against the militant hub.

Military airstrikes have hit suspected Taliban hideouts in the region for weeks. On Tuesday, fighter jets targeted the Taliban strongholds of Makeen, Ladha and Nawazkot in South Waziristan, killing at least two people.

The airstrikes follow four high-profile terrorist attacks that killed more than 100 people in the past week. On Sunday, a suicide bomber targeting a military convoy killed 41 people near the troubled Swat Valley. Militants also bombed a U.N. office in Islamabad, a crowded market in Peshawar and took soldiers hostage inside the army's main headquarters.

Pakistan's government says most of the militant attacks in the country are planned in the tribal regions.

The Pakistani military has been preparing for months to expand an offensive in the region. Officials say the assault will begin soon. U.N. observers say some 80,000 civilians have fled the tribal region in anticipation of a new offensive.

Even as the army prepares for a South Waziristan operation, thousands of troops continue to patrol the Swat Valley, where the government said in late May it was close to declaring victory.

On Tuesday, the Pakistani military said that troops searching for militants encountered some 33 militants who voluntarily surrendered in the last 24 hours. Soldiers reporters several clashes, which killed five suspected militants and wounded two soldiers. The military's claims have not been independently confirmed.

Some information for this report was provided by AP and Reuters.