NATO is deploying eyes in the sky and on the Baltic Sea to protect cables and pipelines that stitch together the nine countries with shores on Baltic waters.

After a series of suspected undersea cable cuttings, NATO has launched a new surveillance and deterrence mission to protect critical infrastructure under the Baltic Sea.

Sweden has opened a preliminary investigation into suspected aggravated “sabotage” and ordered the detention of a vessel in the Baltic Sea suspected of damaging an underwater fiber optic cable connecting Latvia and the Swedish island of Gotland earlier that day.

The Nordic country has opened an investigation into the damage, just weeks after NATO stepped up its military presence in the area following a series of similar incidents.

Sweden detained a vessel suspected of damaging a subsea data cable connecting it with Latvia, the third such incident in the Baltic Sea in the past three months.

A Bulgarian shipping company on Monday denied that one of its ships had intentionally damaged an underwater fiber optic cable connecting Latvia and the Swedish island of Gotland.

An underwater fiber-optic cable belonging to the Latvian State Radio and Television Broadcasting Center (LVRTC) was significantly damaged on Jan. 26, reportedly due to external impact, according to LVRTC representative Vineta Sprugaine.