At least 26 people including four civilians have been killed in clashes between tribal fighters and soldiers in northwest Pakistan, the military and residents said.
Major General Waheed Arshad, the military's spokesman, said that Sunday's fighting occurred in North Waziristan, near the Afghan border.
Security forces launched an operation against the fighters in the mountainous area south of the town of Mir Ali after a military convoy was attacked overnight, Arshad said.
Twenty fighters were killed and 15 were wounded, while two soldiers died and six were hurt, he said.
Local residents told the AFP news agency that four civilians also died, including three women.
Opposition reinforced
Pakistan has seen a wave of violence since July, when a peace agreement with tribal leaders broke down in North Waziristan and army commandos stormed the Red Mosque in the capital, Islamabad.
The violence has reinforced opposition among many Pakistanis to the support of the country's president, General Pervez Musharraf, for the so-called US-led "war on terror".
Musharraf has said "terrorism and extremism" are the biggest challenges the country faces and has called for reconciliation among political parties to tackle it.
US officials have warned that al-Qaeda may be regrouping in North Waziristan.