MANAMA - Pirates have fired small arms weapons at a U.S. Navy supply ship off the coast of Eastern Somalia, the first attack of this kind since last year's surge in pirate attacks, the U.S. Navy said on Thursday.

The USNS Lewis and Clark was chased for about an hour on Wednesday morning by two pirates skiffs, but neither came closer than about one nautical mile to the U.S. vessel, the U.S. Navy's Fifth Fleet said in a statement.

The small arms fire fell well short of the U.S. ship which speeded up to evade the skiffs.

The USNS Lewis and Clark earlier served as a temporary detention facility for suspected pirates arrested at sea, but its operations are now limited to providing supplies to other U.S. ships operating in the area.

Somali pirates have increased their activities in recent weeks, defying the presence of international navies in the area.

There have been 97 attempted attacks on merchant vessels in the Gulf of Aden in 2009, 27 of which have been successful, according to the U.S. Navy.

In the latest incident, Somali pirates on Thursday seized a small Dutch vessel with at least eight crew in the Gulf of Aden.

Somalia