ISLAMABAD - The US-led international efforts to defuse Indo-Pak tension in the wake of Mumbai carnage have proved futile so far because of India's refusal to drop its demand for the handing over of banned Jesh-e-Muhammad chief, Maulana Masood Azhar as well as Dawood Ibrahim and Tiger Memon, the top Mumbai gangsters. Hence, the relations between South Asian nuclear neighbours are getting worse with each passing day and the official circles here fear that India could resort to aggression against Pakistan in near future. To discuss the volatile situation, Pakistan has called back its Ambassador to India, Shahid Malik, who will brief the top leadership on his reading of mood in New Delhi. India has also convened an extraordinary meeting of its envoys abroad, including High Commissioner to Pakistan, in New Delhi today (Monday) that would last for two days and discuss the future course of action. "Indians have so far showed no flexibility on the handing over of the wanted persons and they consider Pakistan's crackdown against Jamaat-ud-Daawa as action not enough to meet the expectations of New Delhi," said a senior official here on Sunday desiring not to be named. Pakistan, on the other hand, had made it clear that Dawood Ibrahim and Tiger Memon were not on its soil and it also has no idea about the whereabouts of Maulana Masood Azhar, the official said. As for Hafiz Muhammad Saeed, Jamaat-ud-Daawa's chief, and other persons arrested in the recent crackdown, they could not be handed over to India because of no extradition treaty or any other legal instrument for the purpose between Islamabad and New Delhi. Moreover, he said, Pakistan had asked India to provide concrete evidence about their involvement in Mumbai attacks and after that action could be taken against them in accordance with the country's law. "Because of deadlock over the wanted persons, tension is mounting between Pakistan and India," the official said. However, he hastened to add that the United States and its other western allies were trying their best to avert any possible conflict between Islamabad and New Delhi, fearing it could lead to nuclear showndown between the South Asian neighbours. He said the recently concluded visit of top security advisor, Mehmud Ali Durrani, to Washington was also aimed at taking Bush Administration into confidence over steps taken by Pakistan against Jamaat-ud-Daawa. He also reiterated in Washington Pakistan's resolve and commitment to continue fight against terrorism. He said the United States, however, was more sympathetic to the cause of Indians despite all its efforts for mediation. The Bush administration, he added, has been urging Pakistan to cooperate more with India on Mumbai carnage and help New Delhi nab persons involved in the ghastly act.