Pakistani authorities have declared security on high alert along provincial borders and in major cities and towns across the country after the killing of Bugti tribal leader Nawab Akbar Khan Bugti by security forces on Saturday, local media reported on Sunday.

Protesters took to streets of Quetta, the provincial capital of southwestern Pakistani province Baluchistan, and angry mobs burnt some vehicles and public installations like banks and petrol stations as news of Nawab Bugti's death spread late on Saturday, the GEO Television reported.

Meanwhile, curfew was imposed in Quetta on Sunday for indefinite period of time due to the violence in the area, and security has been tightened at airports, railway stations, bus terminals and key government and private buildings in Baluchistan, said the report.

Red alert strict security arrangements were made especially at border of Sindh, Baluchistan and Punjab provinces and exit and entry routes of the big cities including southern Pakistani coastal city Karachi and major eastern city Lahore, it said.

Nawab Akbar Bugti, leader of the Bugti tribe and the driving force behind the anti-government rebellion in Baluchistan was killed in a military operation in Dera Bugti district on Saturday.

Some 37 armed tribals including the tribal leader Bugti and 21 security personnel were killed in the fierce clashes in Bhambhoor area of Dera Bugti district, some 250 km southeast of Quetta, which started on Friday and continued on Saturday.

Seventy-nine-year old Nawab Akbar Bugti, a former chief minister of Baluchistan, went underground last year, joining militants who have been waging an armed insurgency for a long time.

(Xinhua News Agency August 28, 2006)