U.S. prisoners of war-including downed pilots-will be released immediately "if the United States ceases its bombings and other interventions in Laotian affairs," Prince Soupanouvong, the Pathet Lao leader said Sunday in an interview published in a Swedish newspaper.

Vice President Spiro T. Agnew said last week that if all American troops were immediately withdrawn from Vietnam, "it would be followed by a wave of far right, irresponsible sentiment" potentially more harmful "than any of the leftwing excesses that are taking place today."

U.S. Command disclosed yesterday the second "protective reaction" air strike inside North Vietnam in three days, the 22nd this year.

A Navy bomber on escort duty in the Laotian panhandle fired at a rebel surface-to-air missile site 30 miles northwest of the demilitarized zone and about a mile inside North Vietnam.

In Cambodia, the South Vietnamese headquarters claimed its troops killed 200 North Vietnamese in Cambodia with the backing of U.S. planes. Only six ARVN men were wounded, according to Saigon.

In South Vietnam, U.S. helicopters broke a ring of Vietcong fire Sunday to resupply a South Vietnamese artillery outpost under siege for 12 days. Most of the helicopters were called back before reaching the base after the North Vietnamese downed one chopper.