QUETTA, Pakistan, Feb. 9 (UPI) -- Pakistani cities in southern Baluchistan province were left without natural gas when militants attacked a major pipeline, Iranian state media said.

Militants using dynamite blew up a key pipeline near the provincial capital of Quetta, disrupting regional gas supplies, Iran's state funded broadcaster Press TV reports.

Press TV said the U.S.-led invasion of Afghanistan caused many militants to cross the border into the volatile border regions in Pakistan.

No group claimed responsibility for the attack. Pakistani ties with Iran soured in the wake of an Oct. 19 bombing at a conference between Shiite and Sunni groups in southeastern Iran. The attack killed several senior commanders of Iran's elite Revolutionary Guard Corps.

The Pakistan-based Jundallah claimed responsibility for the attack.

The latest attack comes as both sides move closer to formal agreements on a long-delayed natural gas pipeline from Iran's South Pars gas complex in the Persian Gulf. Security in Baluchistan was raised as a concern during negotiations for the project in 2009.

Tehran last week blamed foreign elements for attempting to destabilize Iran from its eastern border with Pakistan and Afghanistan.

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