OSLO, Jan 5 (Reuters) - Latvian police have found no evidence linking a ship docked in the port of Liepaja to damage to an underwater telecoms cable in the Baltic Sea but is investigating the incident further, authorities said on Monday.

The Baltic Sea region is on high alert after a string of power cable, telecom link and gas pipeline outages since Russia invaded Ukraine in 2022, and the NATO military alliance has boosted its presence with frigates, aircraft and naval drones.

The latest cable outage occurred on Friday near Liepaja and investigators on Sunday said they had boarded a ship and initiated criminal proceedings, although they did not name the vessel.

INSPECTED SHIP AND ANCHOR

The incident occurred after Finnish police on December 31 seized a cargo vessel en route from Russia to Israel on suspicion of sabotaging an undersea telecoms cable running across the Gulf of Finland to Estonia by dragging its anchor.

MarineTraffic vessel tracking data show four ships crossing the Lithuania-Latvia cable on their way to Liepaja port on January 2, when the damage was first discovered. Three of those ships remained in the port on Monday.

Latvian police said on Monday they had inspected a ship at Liepaja, including its anchor, as well as technical equipment and logs, and that the crew had voluntarily cooperated with the investigation.

"At present, the information obtained in the criminal case does not indicate a connection of the specific ship with the damage to the optical cable," a national police statement said.

Neighbouring Lithuania's National Crisis Management Centre said on Sunday the cable ran from Sventoji in Lithuania to Liepaja, two coastal towns some 65 km (40 miles) apart, and that it was not immediately clear what caused the outage.

(Reporting by Nerijus Adomaitis and Anna Ringstrom; editing by Terje Solsvik and Mark Heinrich)