The accident came as the Solomon Islands declared April 23 a national day of mourning for the 43 people killed when an 8.1-magnitude earthquake triggered a tsunami that crashed through coastal villages earlier this month. Another 7,000 people have been left homeless.

The Taiwanese vessel had been returning to the western town of Gizo after delivering aid supplies to outlying islands when it struck a reef, Taiwan's Ambassador to the Solomon Islands, George Chan, said.

Chan said the reef may have been uncharted or a new obstacle thrown up by the April 2 quake.

"The U.S. helicopter helped us to lift the Red Cross workers and our medical team (off the ship) to ... Gizo," Chan told The Associated Press. "I was told they were safely evacuated."

Thirteen Red Cross workers from New Zealand and the Solomons as well as four medical workers from Taiwan were among those lifted off the ship, along with two medical patients and an injured member of crew, he said. Another 13 crew remained on the grounded vessel.

The helicopter is from the U.S. Navy supply ship USS Frederick W. Stockton that is assisting with tsunami relief, he said.

Solomons police said the stricken vessel was taking on water as waves crashed over its stern and there were fears it could founder.

Two "police vessels made a strong effort to tow the trawler off the reef but snapped three tow lines during the attempt," police said in a statement released in the capital, Honiara.