Norway's coast guard is pursuing a Russian trawler with two Norwegian fishing inspectors on board, officials say.
The inspectors are said to have stopped the trawler, the Elektron, on Saturday on suspicion of illegal fishing in the Barents Sea.
The ship was directed to head to Norway - but unexpectedly changed course.
Norwegian navy spokesman John Espen Lien said the trawler is now "going back and forth" with no real course.
He said the Elektron was stopped in the Svalbard archipelago in the Arctic, in waters claimed by Norway.
"The ship was transporting various types of illegal equipment, including nets which pick up just about everything, including small fish and fry," he told the AFP news agency, reports BBC.
Russian Foreign Ministry has asked Norwegian authorities to provide full information on the incident pertaining to the trawler Elektron, which Norwegian naval forces are pursuing in the Russian economic zone of the Barents Sea some 270 miles away from Murmansk.
"All the necessary measures to solve the problem will be taken within as short a period of time as possible after we get the needed information," a spokesman for the Foreign Ministry said.
The Elektron's captain said in an urgent message to the Murmansk trawler fleet radio center Monday night the ship needed help. The message was received at around 19:00 hours Moscow time (15:00 hours GMT)
An hour after that, the crew of another Russian trawler that had arrived in the problem area found that the Elektron was encircled by four ships of the Norwegian coastal guard, informs ITAR-TASS.
Photo: AFP P.T.