PESHAWAR, Pakistan — Suspected Islamist militants blew up a girls school close to the main city in northwestern Pakistan on Tuesday, police said. The school was empty at the time of the blast and no one was injured.

A timed explosive device is believed to have caused the explosion that badly damaged the school on the outskirts of Peshawar, police officer Hamdullah Khan said.

Al Qaeda and Taliban militants hold sway across much of northwest Pakistan near the border with Afghanistan and have often targeted girls schools in both countries because they believe that women should not be educated.

The military has launched large offensives across parts of the region in an attempt to rein the militants in, but they remain strong in much of the mountainous, lawless zone.

Prime Minister Yusuf Raza Gilani said Tuesday that the global fight against terrorism requires not just a military solution but also gaining the trust of civilians in regions where insurgents operate.

"No war against terrorism can be won without the support of the people," Gilani told a crowd in the eastern city of Multan as part of Eid al-Fitr celebrations at the end of the holy Muslim month of Ramadan.

Winning over the hearts and minds of the civilian population was crucial in assisting the military offensive in the northwestern Swat Valley that ousted Taliban militants from power in July, Gilani noted.

The army launched the Swat offensive in April after local Taliban leaders, who had imposed their harsh interpretation of Islam on residents there, violated a peace deal with the government and expanded into Buner, a district within 100 kilometres of the capital, Islamabad.

Gilani also said Pakistan will not allow terrorists to plot attacks on its soil against other countries, including archrival India.

The comment came a day after the leader of a banned Pakistani Islamist group that India accuses of carrying out attacks on its financial capital late last year was placed under house arrest again.

Pakistani police prevented Hafiz Muhammad Saeed from leaving his home Monday. Saeed is a founder of Lashkar-e-Taiba, which New Delhi says masterminded the commando-style assault that killed 166 people in Mumbai last November.

Yahya Mujhaid, a spokesman for Saeed, condemned the arrest as illegal and unconstitutional.

Pakistan detained Saeed in December, but a Pakistani court freed him from house arrest in June saying there was not enough evidence to hold him.

The prime minister said Tuesday that more evidence tying Saeed to the Mumbai attacks was needed for a criminal case to proceed.

"The government has taken Hafiz Saeed in custody, but further action against him depends on proof available," Gilani later told reporters.

In the northwest, police acting on a tip recovered arms, ammunition and explosives Tuesday hidden near Kohat town -- the scene of a suicide bombing Friday that killed more than 30 people, police chief Dilawar Bangash told The Associated Press.