Sweden has deployed several naval ships in the waters west of the coastal city of Gothenburg to investigate a possible underwater violation of Swedish territory.

In a statement, Swedish naval inspector Jan Thörnqvist said Thursday the investigation was prompted by a reported sighting from a reliable source of a suspected submarine.

Thörnqvist said the ships were sent to the scene to analyze the sighting. But he declined to give any details or confirm media speculation that the sighting is a foreign submarine or if espionage is suspected.

The naval inspector says Sweden is using all available appropriate resources, but said he would not discuss the observation until the Navy has completed its analysis.

No further information was available.