NATO announced a new mission on Tuesday to better protect critical underwater infrastructure in the Baltic Sea with significantly more ships, aircraft and drones, as concerns about Russian aggression in the region grow.

The Baltic Sentry operation comes amid mounting European fears of sabotage after a string of murky disruptions to underwater cables in the sea that borders Russia.

NATO countries on the Baltic Sea met in Helsinki on Tuesday, looking to boost security following the suspected sabotage of undersea cables, widely blamed on Russia. NATO said in late December it would increase its presence in the region following the suspected sabotage of undersea cables between Finland and Estonia but it has yet to announce an official operation.