Published Friday, 04 November 2011
It is understood that the ship, the MV Saoirse, is carrying 15 passengers and crew members in total.
Along with a Canadian vessel, it is being led to Israel by the navy.
It has been reported that no-one was injured in the operation.
Irish Ship to Gaza spokesperson Laurence Davis said: "We are very concerned for the safety of all those aboard the Irish and Canadian boats.
"We call upon all people of conscience to demand their immediate release."
In May 2010, Israeli troops stormed aid ships leaving nine dead.
At the time, Shane Dillon, an Irish activist held by the troops, described the attack as an inhumane act on humane people.