WASHINGTON — The House approved a bill yesterday meant to stop Burma’s rubies and high-quality jade from entering America. It tightens already tough sanctions against a ruling regime that killed peaceful protesters and Buddhist monks in September.

The bill’s sponsors said they want to stop the military leaders in Burma from dodging American sanctions by laundering gemstones in third countries before selling them in America.

International outrage at the September crackdown failed to spur change, lawmakers said, but fresh sanctions would hurt the regime by curbing profit from the gem trade.

“Burma’s generals fund this repression of their own people by selling off the country’s natural resources, especially oil and gems, leaving the Burmese people in poverty,” Rep. Tom Lantos, a Democrat, said in a statement. Tightened sanctions would “ensure that the United States stands up to these thugs.”

A State Department spokesman, Sean McCormack, said Burma has responded to the world’s calls for an improved human rights record “with empty gestures aimed only at gaining time for it to reinforce the status quo.”

To avoid American sanctions, the Burma regime tries to hide the origin of the gemstones it ships to America, according to the bill, which passed by voice vote: “For example, over 90% of the world’s ruby supply originates in Burma, but only 3% of the rubies entering the United States are claimed to be of Burmese origin.”