Latvia's prime minister says her government has reached out to Sweden and other Baltic Sea allies in NATO for assistance as it investigates the cause of damage to an underwater fiber-optic data cable running to Sweden.

An undersea data cable between Latvia and Sweden was damaged early on January 26, the latest in a series of similar incidents in the Baltic Sea in which critical seabed energy and communications lines are believed to have been severed by ships traveling to or from Russian ports.

Multiple undersea cables and pipelines in the Baltic Sea have been damaged in recent months, raising suspicions of sabotage.

Direct challenges to Baltic security include regional aggression waged by Russia and policies of Belarus complementing the aims of Moscow. The conventional warfare in countries across the border from the Eastern Flank of NATO and the EU is aggravated by civilian displacement and migration from Ukraine and the Middle East.

Following damage to an undersea cable in the Baltic Sea, Latvia has made initial progress in the search for the cause. During investigations at the

Earlier this month, NATO began a new mission dubbed "Baltic Sentry" which included frigates, maritime patrol aircraft and a fleet of naval drones to provide "enhanced surveillance and deterrence" in the Baltic Sea which the transatlantic alliance says is to protect undersea cables and pipelines.

Latvia on Sunday said it had sent a warship to investigate the latest apparent act of sabotage in the Baltic, as Sweden reported at least one undersea optic fibre cable linking the two countries had been damaged.

The Stockholm prosecutor's office announced on Sunday evening that an investigation has begun into possible sabotage in the Baltic Sea, as well as the seizure of a ship suspected of damaging an underwater cable between Sweden and Latvia.

Shipping firms may need to pay a fee to use the Baltic Sea, one of the world's busiest shipping routes, in order to cover the high costs of protecting undersea cables, Estonia's defence minister said on Wednesday following a spate of breaches.

Nato countries have stepped up patrols to protect critical underwater infrastructure in the Baltic Sea, which is bordered by eight countries, and other waters. A Royal Navy submarine was ordered to surface last November close to a suspected Russian spy ship which was loitering over undersea infrastructure in UK waters.

RIGA, Jan. 26 (Xinhua) -- An underwater fiber optic cable connecting Latvia and the Swedish island of Gotland in the Baltic Sea was damaged early on Sunday, the cable's owner, SJSC Latvian State Radio and Television Center (LVRTC), informed.

NATO launched 'Baltic Sentry', a new naval mission to prevent attacks on cable infrastructure in the Baltic Sea. The alliance says Russia is to blame for recent incidents, but can increased NATO patrols make a difference?