A South Korean fishing boat sank off northern Japan with 27 people aboard and an extensive air-sea search found no trace of them, maritime officials said Tuesday.

Two patrol ships and two aircraft joined the search in the Pacific about 550 miles off the northern Japanese coast where the 290-ton fishing boat Sang Young No. 35 went down late Sunday, the officials said.The crewmen had been reported drifting aboard two rubber rafts in the stormy sea after their ship sank.