The Defense Department said yesterday that two of the 23 Americans killed during the invasion of Panama died from "friendly fire" coming from U.S. forces, and 19 of the 324 wounded were hit by rounds fired from U.S. positions.

In a statement issued in response to an article in Newsweek magazine, the Pentagon said two U.S. servicemen hit by their own troops during the night operation died at Rio Hato, where the Army's 82nd Airborne Division staged a parachute assault to seize a key base held by the Panama Defense Forces.

"In the case of one additional serviceman killed in action," the statement said, "it has not been determined if his death was a direct result of friendly or enemy fire." This case is still under investigation, the Pentagon said.

Aside from the 19 cases of wounds inflicted by friendly fire, the statement said there were "an additional 21 . . . injured by either friendly or enemy fire during the intense night fighting in the vicinity of the Commandancia," which was the military headquarters of Gen. Manuel Antonio Noriega.

Newsweek, quoting unidentified military sources, reported that nine of the 23 U.S. battle deaths and 60 percent of U.S. injuries probably were the result of "friendly fire."