WASHINGTON, Dec. 20, 1989 (UPI) -- About 7,000 Army Rangers, paratroopers and other soldiers backed by light tanks and helicopter gunships were flown into Panama to join 13,000 American troops already there for Wednesday's attack, officials said.
And during the day, they were reinforced with other infantry and military police units to bring the total troop strength in Panama to about 24,000.
The assault forces -- on a mission called ''Operation Just Cause'' -- in several cases were assisted by U.S. units, including Marines, already in Panama, which moved into place to seize objectives or block transportation routes to prevent Panamanian Defense Force units from moving out of their bases.
A typical U.S. battalion is 600 to 800 men, and a brigade typically has 1,000 men.
Gen. Colin Powell, chairman of the Joint Chiefs of Staff, provided this breakdown of the U.S. units involved and how they were utilized.
Powell said the ''in place forces'' included the 193rd Infantry Brigade, which was reinforced this year with Marine units, by a battalion from the 7th Infantry Division at Fort Ord, Calif., and by a mechanized battalion from the 5th Infantry Division from Fort Polk, La.
Those troops introduced were a brigade from the 82nd Airborne Division from Fort Bragg, N.C., two Army Ranger battalions, and ''selected special operating units.''
Sent later Wednesday were elements of the 7th Infantry Division from Fort Ord and the 16th MP Brigade from Fort Bragg.
Powell said the attack began just before 1 a.m. with this order of battle:
--Task Force Atlantic (on the Atlantic, Caribbean side) consisted of one battalion from the 7th Infantry Division and one battalion from the 82nd Airborne. Its job was to secure several critical sites in the southern portion.
It seized the prison at Gambo, where 47 PDF prisoners involved in the Oct. 3 coup against Noriega were freed. It also secured the ''electrical distribution station'' at Cerra Tegre and the Madden Dam and secured the Colon area, neutralizing the PDF's 8th Infantry Co. and its naval infantry unit.
--The Semper Fidelis task force was composed of a Marine rifle company and light armored vehicles. It secured the Bridge of the Americas and the area around Howard Air Force Base.
--Task Force Red (to the west at Rio Hato): A Ranger battalion parachuted onto Rio Hato, neutralized the area and dispersed the PDF's 6th and 7th companies. It was the 7th Co. that came to Gen. Manuel Noriega's aid during an unsuccessful Oct. 3 coup attempt.
--Task Force Bayonet (in central sector): consists of mechanized battalion, a platoon of light tanks, and the 5th Battalion of the 87th Infantry. Its mission was twofold: secure major U.S. facilities in the region and seize the Commandancia, Noriega's PDF headquarters. It neutralized the 1st Public Order Co. and 2nd Public Order Co. and elements of 6th and 7th.
Another unit of same task force was flown across entrance of the Canal to block the PDF's 5th Infantry Co. at Fort Amador.
--Task Force Pacific and a second Red Ranger task force: The Rangers secured the international airfield east of Panama City and the Pacific Task Force's 82nd Airborne units parachuted onto the field to block Panama's Battalion 2000 farther east and to move west to block other units.
At 1:55 a.m., the first elements of the 82nd Airborne arrived aboard C-141s and conducted a parachute assault at the international airport. Several hours later, another 10 C-141s brought in the second half of 82nd Airborne troops to parachute in.
''We also took special actions to immobilize PDF Navy and aircraft that could have been used for escape purposes,'' said Powell.
Powell said U.S. forces were supported by Air Force and Army gunships and Special Forces reconnaissance surveillance units.