Authorities are questioning the crew of a Maltese-flagged ship that collided with a Chinese fishing boat over the weekend, killing at least two sailors and leaving 17 others missing, Chinese state media reported Monday.

The ship's Greek captain and 19-member mostly Filipino crew said they were unaware they had collided with another craft in heavy fog early Saturday morning, the reports quoted Xu Zhiyong, a border checkpoint officer in the port of Beilun in the eastern province of Zhejiang, as saying.

The ship, the Catalina, did not stop following the accident but was later ordered into port for investigation and docked Saturday night in Beilun where it was boarded by Chinese officers who conducted an investigation, the reports said. The captain, second mate, officers of the deck and other officers were taken off the ship for further questioning.

The investigation was being hampered by a lack of direct evidence and may take some time, Xu was quoted as saying.

Navy ships and other craft are searching for survivors in the area of crash, about 150 kilometers (93 miles) off the coast of Zhejiang, just south of Shanghai.