AMSTERDAM/DAKAR (Reuters) - Two Dutch airmen died after an Apache attack helicopter serving with the United Nations peacekeeping mission in Mali crashed in the north of the country on Tuesday afternoon, Dutch officials and the U.N. said.

Captain Rene Zeetsen, 30, was killed in the crash and First Lieutenant Ernst Mollinger, 26, died later in a field hospital in Gao from his wounds, General Tom Middendorp, the head of the Dutch forces, told a news conference.

The U.N. mission in Mali (MINUSMA) said in a statement the accident took place during an exercise conducted by the Dutch contingent about 42 km (26 miles) north of the town of Gao.

"The two crew members lost their lives in this accident," it said. "A medical team was immediately deployed to the site of the accident, but was not able to save the helicopter’s crew."

The Netherlands has been involved in the U.N. mission in Mali since last year. Its armed forces have contributed four Apaches and three Chinook transport helicopters.

(Reporting by Thomas Escritt and David Lewis; Writing by Bate Felix; Editing by Tom Heneghan)