WASHINGTON — For the second time in two months, President Bush announced sanctions against Burma to punish the military-run government and its backers for the recent violent crackdown on pro-democracy protesters.

Mr. Bush ordered the Treasury Department today to freeze the financial assets of additional members of the repressive military junta. He also acted to tighten controls on American exports to Burma and called on the governments of China and India to do more to pressure the government of the Southeast Asian nation.

“Monks have been beaten and killed. Thousands of pro-democracy protesters have been arrested,” Mr. Bush said in the Diplomatic Reception Room of the White House.

“Burma’s rulers continue to defy the world’s just demands to stop their vicious persecution.”

Last month, tens of thousands of people turned out for rallies, which started as protests of sharp fuel increases and later snowballed into the largest show of government dissent in decades. The junta claims that 10 people were killed when troops opened fire on demonstrators to disperse them, but diplomats and dissidents say the death toll is likely much higher.

In response, the Bush administration froze the assets that individuals responsible for the crackdown have in American banks or other financial institutions under American jurisdiction. The administration also prohibited any American citizens from doing business with the designated individuals.

Among those targeted for the sanctions were the junta leader, Senior General Than Shwe, and the no. 2 man in the military regime, Deputy Senior General Maung Aye.

The crackdown also prompted first lady Laura Bush to make personal appeals for support for Burmese citizens, saying the acts of violence “shame the military regime.”