Islamabad  - Warring Sunni and Shiite Muslims in a remote Pakistani tribal region on Saturday announced an interim ceasefire after months of clashes killed more than 500 people and wounded hundreds more.

Meanwhile, troops killed at least seven militants in the raging offensive against insurgents supported by al-Qaeda and Taliban fighters near the Afghan border.

Tribal elders from the rival Bangash and Toori tribes brokered the truce in a meeting arranged by the top administrator of Kurram tribal district, Muhammad Azam Khan, in Islamabad.

The chieftains agreed to a truce until December 31 to defuse the situation in the violence-plagued mountain area near the Afghan border. Both sides will also exchange prisoners.

Khan said the tribesmen would again meet on October 6 to bring lasting peace to Kurram, which was in the grip of fierce fighting since April 2007.

Government forces also made infrequent attempts to quell the violence, using helicopter gunships to pound positions held by militants who joined the Sunni Bangash tribesmen after crossing into Kurram from adjoining regions.

The tribal elders on Saturday accused "the common enemy across the border" of having "sinister designs" and of inciting sectarian violence in Kurram, which they vowed to put an end to.

Shiite-dominated areas in Kurram, particularly its main town of Parachinar, have been cut off from the rest of the country through land routes over the last year, causing severe shortages of food and medicine.

Khan vowed to reopen a key link between the towns of Parachinar and Thal as soon as possible to transport food and medical stores. Earlier, Sunni fighters were accused of killing truckers delivering supplies to Shiites.

Meanwhile officials said at least seven pro-Taliban insurgents were killed on Saturday when security forces pounded their hideouts in the restive Bajaur tribal district, a sanctuary for al-Qaeda and Taliban fighters.

Helicopter gunships and artillery targeted the militant positions in the Loi Sam and Tang Khata areas where the rebels have developed a maze of trenches and tunnels, a security official said.

According to Major General Tariq Khan, chief of the Frontier Corps paramilitary force, more than 1,000 militants, including some foreign commanders and their supporters, were killed in intense fighting that started early August after scores of rebels attacked a strategic security post in Loi Sam.

Khan said it would take another six weeks of military operations to clear Bajaur of militants. (dpa)