Twelve members of the Washington news media were flown in secrecy today to witness the mock invasion of the mythical Marxist nation of Sanna, where Americans had been taken hostage after the government collapsed.

The routine military exercise at this sprawling military base was used as the second test of whether the Pentagon and the press can cooperate in coverage of U.S. military actions.

The press witnessed a portion of Double Eagle 85, a training exercise for 4,000 members of the 101st Airborne Division. The action included mock helicopter gunship assaults, search and secure movements by infantry making their way through the heavily wooded Kentucky countryside, and a nighttime treetop arrival at U.S. forces' headquarters, heavily camouflaged in a stand of pines.

The reporters were told the troops were fighting to stabilize the political situation in Sanna, and Thursday's actions had the Sannaese on the run after the hostages -- medical students, as was the case in Grenada -- had been freed by the invading troops two days earlier.

Perhaps the most impressive military display witnessed by the reporters occurred when four different types of helicopters were used to secure a meadow, drop off two 105-mm howitzers, and then pick them up after shelling enemy positions.

Col. Dante Camia, the escort officer for the reporters, said of the pool test, "At first blush, I can't help but smile. We've got something to build on."

There appeared to be complete secrecy about the dispatch of the pool, unlike a mid-April exercise when 10 men were sent to Honduras to watch U.S. troops on maneuvers for several days. Word of the pool leaked out before its members departed Andrews Air Force Base outside Washington.

Today's pool was summoned to the Pentagon, where it departed about 1 a.m. for Andrews Air Force Base. The team left at 3 a.m. in two C12 Air Force turboprops for Fort Campbell.

Arriving at the base before dawn, they were flown in UH60 Blackhawk helicopters to a briefing on the fighting and then sent into the field with the troops.

The pool included reporters from The Associated Press, United Press International and Time magazine; UPI and Time photographers; reporters from Newhouse Newspapers, the Los Angeles Times, and Newsday; a reporter from Mutual Radio and a reporter and two others from Cable News Network.