MINGORA, Pakistan, (Reuters) – Pakistan’s government  ordered the army to eliminate militants yesterday, setting the  stage for a major offensive against Taliban fighters battling  security forces in a northwestern valley.

The government’s handling of the Swat valley has become a  test of its resolve to fight a growing Taliban insurgency that  has alarmed the United States.

President Asif Ali Zardari, in Washington for talks, assured  U.S. President Barack Obama on Wednesday of Islamabad’s  commitment to defeating al Qaeda and its allies.

Security forces used jets and helicopters to pound Taliban  positions in Swat, 130 km (80 miles) from Islamabad, as  thousands of civilians took advantage of a break in a curfew to  flee.

With hundreds of thousand of people already displaced by  fighting, aid groups said the new exodus of tens of thousands  was intensifying a humanitarian crisis.

Prime Minister Yusuf Raza Gilani said in a televised address  the militants were trying to hold the country hostage at  gunpoint.