WASHINGTON (AP) _ An Indiana congressman told Secretary of State Warren Christopher in a House hearing today that Christopher could be responsible for genocide and the deaths of hundreds of thousands of people in Bosnia.

Rep. Frank McCloskey, who has already demanded Christopher's resignation, urged the Clinton administration to come to the aid of Muslim civilians besieged by Bosnian Serb gunners in Sarajevo and other parts of the wartorn former Yugoslav republic.

''History will record this happened on our watch, on your watch,'' McCloskey said in an impassioned appeal during a House Foreign Affairs Committee hearing on the North American Free Trade Agreement.

But Christopher dismissed the plea, saying McCloskey wanted to send hundreds of thousands of U.S. troops to Bosnia-Herzegovina - an assertion McCloskey rejected. ''Your very strong feelings on this subject have affected your judgment on other matters,'' Christopher said.

It was an uncharacteristic personal sally by Christopher, who also clashed Thursday with Sen. Jesse Helms, R-N.C., over U.S. policy toward Haiti.

In responding to Helms' blistering attack, Christopher kept his temper under check. His harshest reply was to tell the North Carolinian, a persistent critic of the State Department, not to mistake courtesy for a lack of resolve.

Christopher's tone in dealing with McCloskey, a fellow Democrat, was much sharper.

''I don't see any point in debating this subject further,'' Christopher told McCloskey, who was in Sarajevo two weeks ago and has made a crusade of his concern for the Muslim victims of ethnic bloodshed.

He accused President Clinton and Christopher of a ''shameful about-face'' on Bosnia, of issuing ''hollow warnings'' to the Serbs and said safe areas set up by the United Nations for civilians were ''concentration camps.''

''Genocide is taking place in Bosnia,'' McCloskey said, reading from a prepared statement. And, he said, some State Department officials shared this view.

Clinton proposed in his presidential campaign last year permitting weapons to get to the Muslim-led government, who are overwhelmingly outgunned by the Serbs, and bombing Serb artillery sites.

In May, Christopher took the proposal to NATO allies in Europe. They declined to go along. Several times since Christopher has warned the Serbs that strangling Sarajevo or interfering with food and energy shipments could prompt a NATO attack.

McCLoskey had to cut short his statement because the committee permits only five minutes of questioning by each member. As it was, he ran a minute or two over. Christopher sat stern-faced through the attack, then dismissed McCloskey's assertions with a few sentences.

McCloskey later said he had never proposed sending U.S. troops to Bosnia, but simply wanted the administration to implement a policy of lifting the arms embargo against the Muslim-led government and bombing some Serb artillery positions.