PM Manmohan Singh speaks to US Prez

Sources, however, did not say whether the two leaders discussed the bin Laden issue.

A PMO spokesman said Singh and Obama discussed further growth and development of Indo-US relations and the situation in the region.

"It was a warm conversation which covered wide-ranging subjects", he said.

This is the first conversation between the two leaders since the killing of Osama on May 2 in a raid by US Special Forces in the garrison city of Abbotabad.

Singh had termed bin Laden`s killing as a significant step forward and asked the international community and Pakistan in particular to work comprehensively to end the activities of all terror groups.

The Prime Minister had hoped that bin Laden`s elimination would deal a "decisive blow" to al Qaeda and other terrorist groups".

The telephonic talk came on a day when the US President raised questions about the possibility that "some people inside of government" in Pakistan may have been involved in providing support structure for the slain terrorist.

"We don`t know whether there might have been some people inside of government, people outside of government, and that`s something that we have to investigate and more importantly, the Pakistani government has to investigate," he told a news channel in his first interview after bin Laden`s death.

"We think that there had to be some sort of support network for bin Laden inside of Pakistan. But we don`t know who or what that support network was," Obama said.