MILAN, Italy, Dec. 28 (Xinhua) - Two people were killed and four went missing after two merchant ships collided while maneuvering in the Italian northern port of Ravenna on Sunday.

"Two victims have been ascertained so far. Five people have been hospitalized in Ravenna in good conditions, while four are missing," Ravenna Mayor Fabrizio Matteucci told Rai State television.

All people involved in the wreckage, Matteucci said, were Turkish nationals aged between 25 and 55. He also added that rescue efforts were "gigantic" amidst "dramatic and perilous sea conditions."

According to local media, a Turkish-flagged vessel sank after colliding with a Belizen-flagged ship probably due to low visibility, because of a thick fog and an intense snowfall in the area.

ANSA news agency said one of the vessels was carrying fertilizers, while the other one was unloaded.

Vessels, helicopters and firefighter teams were taking part in the search and rescue operations which local reports said were getting more difficult amidst wind.