Norwegian initial report: Unclear what led to ship collision

COPENHAGEN, Denmark (AP) — A preliminary investigation into the sinking of a Norwegian naval frigate following a collision with an oil tanker earlier this month has yet to identify a single reason for the incident, authorities said Thursday.

Norway's Accident Investigation Board says it wanted to "provide a brief update" and noted that the accident was "complex."

The 134-meter (442-foot) KNM Helge Ingstad collided Nov. 8 with Maltese-flagged oil tanker Sola TS in a harbor north of Bergen, tearing a large hole in the frigate's side.

The agency said "control of the rudder and propulsion was lost" after the collision, and the frigate headed "uncontrolled" to the shore where it started sinking.

The frigate's 137-member crew was evacuated and eight people onboard were slightly injured.

The tanker was only slight damaged in the collision.

The agency also issued a safety alert to the Norwegian navy after finding out that the frigate lacks watertight compartments, and urged the navy to find out whether four other vessels in the frigate class had the same problem.