The Congress Wednesday asked the government to probe the source of funds of social activist Anna Hazare's massive anti-corruption crusade and also wondered why the US suddenly chose to remark on the movement.

"It needs to be considered whether there is any power which is supporting this movement which wants to destabilize not only the government but the country. We need to take the US statements (on the protest) seriously," Congress spokesperson Rashid Alvi told reporters.

"The US never supported any movement in India since its independence. For the first time, the US said that Anna Hazare's movement should be allowed and there should be no obstruction to it. What was the need for the US to give this statement," he asked.

He said India would exercise "appropriate democratic restraint" in dealing with the peaceful protest.