A controversial forest-thinning bill aimed at curbing wildfires and insect attacks has been passed by the US House of Representatives.

The Healthy Forests Restoration Act, earlier endorsed by a congressional committee, was approved by the House of Representatives in a 256-170 vote.

The legislation, which now heads to the Senate Energy Committee, calls for the removal of small underbrush and trees on 20 million acres of land.

Many Democrats and environmentalists have criticised the plan, saying it would allow logging companies to cut old-growth trees while not reducing the threat of fires.