HELSINKI, Nov. 9 (Xinhua) -- Finland is investigating alleged interference with the GPS satellite navigation service in Northern Finland, and key parliamentarians in the national security sector expressed their concern on Friday.

The Finnish Air Navigation Service gave early this week a warning to the air traffic that satellite positioning based on the GPS system could be unreliable in a large area.

The situation assumed political dimensions on Friday as Matti Vanhanen, the chairman of the Parliamentary Foreign Affairs Committee, said that such "infringement is comparable to a border violation".

Vanhanen reminded on national TV, Yle that it has been a Finnish policy for a long time that border violations are made public without a delay. Foreign Minister Timo Soini refused to give any comment, but said the Committee would be informed.

The disturbance occurred while a NATO exercise in Northern Norway was coming to a close. Norwegian media has attributed comparable interference with GPS detected in Norway to Russia.

Ilkka Kanerva, the chairman of the Parliamentary Defense Committee, said that in areas where "civilian and military activities border on each other", unpredictable and dangerous situations could be encountered.

Talking to Yle, Heikki Isonmaa, the operational director of the Finnish Air Navigation Service (ANS), refused to speculate where the interference had come from. He said no information had reached the ANS that flights would have been affected.

The warning regarding GPS was the first of its kind in Finland.

The NOTAM (short of "Notice to Airmen") that was in force on Tuesday and Wednesday covered areas extending from the airport of Kittila northwards to the Norwegian border and eastwards to the Russian border.