STOCKHOLM, Sweden -- Suspected alien frogmen tried to escape through a military blockade in the Karlskrona archipelago but Swedish armed forces apparently kept them back with submachine gun fire and shock bombs, defense officials said Sunday.
'We shall protect our installations and see to it that none (of the intruders) gets in or out,' said Vice Adm. Bror Stefenson, Sweden's defense staff chief.
The navy is convinced it has trapped an unknown number of alien frogmen and mini-submarines inside Karlskrona's basin, a restricted zone on the Baltic Sea 250 miles south of Stockholm.
A helicopter dropped six shock bombs at noon local time Sunday in waters north of Sturko island in the eastern part of the Karlskrona basin. No result was reported.
Other action in Sweden's largest-ever submarine hunt occurred in the western part of the basin, which houses a key naval base behind a barrier of islands, mine fields and anti-submarine nets.
Late Saturday, soldiers fired submachine guns and helicopters dropped five shock bombs into the water after 'several unknown persons' tried to come up on the shore of Almo island in the northwestern corner of the basin, officials said.
'We don't think anyone managed to get out,' said Lt. Col. Jan-Ake Berg, chief press spokesman at the defense staff. 'We think they had to retreat.'
Troops with submachine guns and police with dogs combed the island in the darkness while helicopters with search lights hovered above but nothing was found, Berg said. He denied newspaper reports that an alien frogman had been wounded by gunfire.
The shooting occurred near where another foreign frogman slipped out through the military blockade late Wednesday by running 500 yards across Almo island and diving into the open sea.
A navy helicopter depth-charged a suspected submarine intruder southwest of the basin just inside Sweden's 12-mile territorial water limit Saturday, officials said.
They said it may have been a full-sized mother submarine waiting for mini-submarines to escape from the basin.
The full-scale hunt, which began Feb. 10, is taking place in the same area where a Soviet submarine grounded in 1981.
