QUETTA: Gunmen, riding motorcycles, shot dead four policemen in Quetta, capital of Pakistan's troubled southwestern province of Balochistan Saturday, police said.

The attackers sprayed bullets at police on a routine vehicle patrol in the capital of the oil and gas rich province, which is plagued by sectarian violence, a tribal insurgency and attacks by Taliban militants.

“Three policemen died on the spot, while one expired at hospital,” senior police official Zubair Mehmood told AFP.

Doctor Noor Mohammad at local government hospital confirmed the death toll.

Gun and bomb attacks frequently target police and security personnel in Balochistan, where insurgents in 2004 began fighting for autonomy and a greater share of the region's natural mineral wealth.

There was no immediate claim of responsibility for the attack.