WASHINGTON: Chairman of the US Joint Chiefs of Staff Admiral Michael Mullen has urged Pakistan to explore “any and all possible ties” between the Mumbai attacks and groups based in Pakistan, said a Pentagon report issued on Thursday.

The report said that the admiral, who visited Islamabad on Wednesday, thanked Pakistani officials for their willingness to work with Indian authorities in a joint investigation into the attacks.

According to the report, during Admiral Mullen’s meetings with President Asif Ali Zadari, National Security Advisor Mahmud Durrani, Chairman of the Joint Committee Gen Tariq Majid, Chief of Army Staff Gen Ashfaq Kayani and Inter-Services Intelligence Chief Gen Shuja Pasha, “all agreed that the tragedy in Mumbai represents a dangerous escalation in the sophistication of extremist attacks that represents an increased threat to the entire region”.

Mr Mullen noted during the sessions recent successes Pakistan’s armed forces had made against extremists in the border region.

“Admiral Mullen also encouraged Pakistani leaders to take more — and more concerted — action against militant extremists elsewhere in the country,” it said.