Amid rumors in South Vietnam that U. S. ground troops had crossed into Laos, ABC news reported last night that their reporters had found a dead American soldier dressed in a South Vietnamese uniform in Laos.

Pentagon spokesmen in Washington continued to deny that any American ground combat troops are involved. White House press secretary Ronald L. Ziegler said, "Our policy is and will continue to be that there will be no U. S. combat troops or advisers in Laos."

Mrs. Nguyen Thi Binh, head of the PRG delegation to the Paris peace talks, claimed yesterday that there are ten battalions of American infantry, artillery, and armor fighting inside Laos.

Later, North Vietnamese and NLF spokesmen said the 7th Battalion of the 17th Calvary Regiment and "several battalions" from the 5th Mechanized Division and the 101st Airborne Division are operating in Laos. The United States called the accusations "all nonsense."

Ambassador David K. E. Bruce reasserted that "no American ground combat forces or advisers will cross into Laos." He said that American air and artillery units are supporting the South Vietnamese incursion -the artillery firing from across the South Vietnamese border.

South Vietnamese officers said Thursday that the heavy fighting in

southern Laos is yet to come, and may come soon.

But the American Command in Vietnam reported Friday morning (Saigon time) that U. S. reconnaissance teams are operating inside Laos. The command said that the patrols have been gathering information in Laos for years, and were merely continuing their work. U. S. troops are also flown into Laos to rescue downed reconnaissance helicopters, the command said.

The command also reported that eight more helicopters were shot down by anti-aircraft fire over Laos yesterday, and ten American soldiers were killed. Two South Vietnamese helicopters, with sixteen persons, including four newsmen, were also downed.

Advancing South Vietnamese troops have met only scattered resistance on the ground so far. But North Vietnamese anti-aircraft fire has taken a serious toll in allied helicopters.

The allied commands have confirmed four helicopters shot down since the offensive started Monday. They with held reports on a number of others on the grounds that such news might jeopardize rescue operations or combat action still in progress.