ISLAMABAD: As tension grows between Pakistan and Iran after a mosque bombing in Iran, Pakistan could find itself increasingly isolated as its western neighbour looks to increase its influence in the region, analysts say.

Jundollah, a Sunni Muslim militant group Iran says is based in Pakistan's southwestern province of Baluchistan, claimed responsibility for a Dec. 15 double suicide bombing in the Iranian town of Chabahar that killed 39 people and wounded more than 100.

Iran has demanded Pakistan take action with Iranian President Mahmoud Ahmadinejad calling this week on his Pakistani counterpart, Asif Ali Zardari, to arrest “identified terrorists” and hand them over to Iran.

Iran says Jundollah fighters find shelter in Pakistan.

Pakistan denies providing shelter for the group.

But in an echo of US demands regarding Taliban sanctuaries in northwest Pakistan, a member of the Iranian parliament's national security and foreign policy committee suggested that if Pakistan didn't act, Iran would.

Analysts say the strong words from Iranian officials add to growing international pressure on Pakistan to take stern action against militants operating out of its territory.

“Iran is ... a major regional stakeholder in Afghanistan and a competitor of Pakistan there. It is therefore likely that Iran is now flexing its muscles on its eastern flank to showcase its regional rise,” the intelligence firm STRATFOR said.

Pakistan and Iran have long jockeyed for influence in Afghanistan, with Pakistan supporting the ethnic Pashtun and Sunni Muslim Taliban and pre-dominantly Shi'ite Iran backing the Taliban's enemies in the old Northern Alliance of non-Pashtuns and some Shi'ite groups. – Reuters