Unidentified gunmen shot dead two Pakistani employees of a contractor to a Malaysian gas company in southern Pakistan, police said on Tuesday.

The killings took place at Gotki, 550 kilometers northeast of Karachi, late on Monday, local police officer Altaf Halepota told reporters.

Jamil Ahmed and Zaheer Ahmed, working for a canteen contractor to Malaysia's Petronas Carigali, were killed when three unidentified gunmen in a car fired on their vehicle, Halepota said.

"It looks like a target killing but it is premature to say anything about the motive behind the attack," he said.

The victims were travelling with two paramilitary guards, who were unhurt and returned fire, but the attackers managed to flee, Halepota said.

Police and paramilitary rangers have cordoned off the area and started searching for the killers.

Gas exploration projects

Petronas Carigali is working on gas exploration projects at Kandanwari gasfield after securing two exploration licences in 2001. Police, paramilitary Pakistan Rangers and private security guards closely guard its operations.

Sixteen foreign hydrocarbon exploration companies are operating in Pakistan, most of them in the north of Sind province which has significant gas reserves.

The shootings took place in an area bordering the southwestern province of Baluchistan where rebel tribesmen have recently stepped up attacks on rail tracks, power and communication lines.

The tribesmen, demanding autonomy and control over natural resources, last month launched rockets attacks on Pakistan's main gasfield at Sui, 75 kilometers north of Gotki. Supplies to millions of users were temporarily cut.