QUETTA, Pakistan: Pakistani paramilitary forces on Friday said they captured a large quantity of arms and detained eight suspected sectarian militants from the troubled southwestern city of Quetta.

Quetta, the capital of oil and mineral rich Baluchistan province which borders Afghanistan and Iran, was recently hit by two sectarian bomb attacks killing nearly 200 Shiites Muslims.

Al-Qaeda linked Sunni militant organisation Lashkar-e-Jhangvi (LeJ) claimed both attacks and threatened further killings of Shiites.

"Our troops raided a house in the Dasht suburb of Quetta and recovered a large quantity of arms and ammunition dumped underground in the courtyard of the house," Colonel Maqbool Ahmad, a senior official of the paramilitary Frontier Corps, told reporters.

Ahmad, who supervised the raid, said they also detained eight militants from the house in Dasht, 25 kilometres (16 miles) south of Quetta city.

"The arrested persons must have connections with sectarian organisations and may lead us to unearth terrorists involved in terrorist activities in Quetta," he added.

The arms and ammunition seized included 120 kilograms (260 pounds) of explosives, 1,000 explosive detonators, guns and rocket-propelled grenades.

LeJ emerged as a spin-off from mujahideen groups which were funded by the US Central Intelligence Agency and backed by the Pakistani intelligence services during the 1980s war against Soviet troops in neighbouring Afghanistan.

An attack on Sunday in a mainly Shiite area in Pakistan's largest city Karachi killed 50 people, bringing to more than 250 the number killed in four major bombings on the minority community in Pakistan since January 10.

Authorities routinely arrest suspects in the aftermath of attacks but the detentions generally lead to few convictions.