An undersea fiber optic cable between Latvia and Sweden was damaged on Sunday, likely as a result of external influence, Latvia said, triggering an investigation by local and NATO maritime forces in the Baltic Sea.

RIGA, Latvia (AP) — Latvian Prime Minister Evika Siliņa said Sunday that 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 data cable running to Sweden.

In a troubling incident, an important undersea data cable connecting Sweden and Latvia was found damaged in the Baltic Sea. This disruption has raised alarms, prompting Swedish authorities to start a criminal investigation into the matter.