The Islamic State group claimed responsibility for the weekend bombing that killed two police officials in restive southwestern Pakistan, officials said Monday.

Analysts say the latest violence is a sign of increasing coordination between Islamic militants and separatists who for years have been targeting security forces and civilians in the oil- and gas-rich Balochistan province bordering Iran and Afghanistan.

The Islamic State group said in a statement on Sunday that it detonated an explosive device a day earlier targeting a Pakistani police vehicle in Kuchlak town near Quetta, the capital of Balochistan. Pakistani officials say the attack killed two officers and wounded two others on a highway.

The Balochistan Liberation Army has previously claimed such attacks, but the Islamic State has carried out similar attacks in recent months.

BLA last month killed dozens of people in gun and suicide attacks on passenger buses, police stations and military facilities.

Abdullah Khan, a senior defense analyst and managing director of the Islamabad-based Pakistan Institute for Conflict and Security Studies, told The Associated Press that the latest claim by the Islamic State indicates that BLA and Islamic militants are now working together on attacks in Balochistan and elsewhere in the northwest.

Balochistan is the scene of a long-running insurgency, with an array of separatist groups staging attacks mainly on security forces. The separatists demand independence from the central government.