Pakistan is sending troops and warplanes into the volatile South Waziristan region, the first steps in a new offensive targeting Pakistani Taliban leader Baitullah Mehsud.
Pakistani officials said warplanes bombed suspected Mehsud strongholds Friday while troops traded fire with militants on the ground.
Mehsud is one of Pakistan's most wanted militants and is blamed for scores of attacks against government and civilian targets. He is also believed to be a key facilitator for al-Qaida fighters in the country.
The latest Pakistani offensive comes as officials are asking refugees to return to the country's northwestern Buner district.
Officials there said the campaign to wipe out Taliban militants is wrapping up. And they said even though many homes were destroyed, they have set up a tent camp with some basic provisions for residents who are ready to return.
An estimated 2.5 million people already have fled fighting in Pakistan's northwest since the military began battling Taliban fighters in the greater Swat valley more than a month ago. Reports from South Waziristan said some residents have fled their homes in anticipation of violence.
On Thursday, the United Nations warned the flood of refugees was close to overwhelming communities that had taken them in. The top humanitarian coordinator for Pakistan, Martin Mogwanja said health and sanitation services in some areas had been pushed past their limits.
Meanwhile the UN World Food Program (WFP) is warning the Pakistani Taliban are increasingly targeting international aid agencies.
Spokesman Paul Risely said the bombing of the Pearl Continental Hotel in the northwestern city of Peshawar earlier this month, which killed nine people, was intended as a message to aid groups.
Caroline Wadhams, a senior policy analyst with the Center for American Progress in Washington, told VOA Deewa Radio the U.S. government is feeling more optimistic about Pakistan's efforts to take on militants. But she also said the Pakistani military is still not doing enough to prevent militant attacks on sites in neighboring Afghanistan.
Also Friday, Pakistani officials blamed Taliban militants for bombing three schools in the Bajaur area but said no one had been hurt.
Some information for this report was provided by Reuters.