Factbox: What is the group challenging Israel on Gaza?

NICOSIA (Reuters) - The Cyprus-based Free Gaza Movement was one of the organizers of a six-ship flotilla that was taking aid supplies to Gaza when it was intercepted by Israeli forces on May 31 and nine activists aboard a Turkish vessel were killed.

Here are some facts about the movement:

WHAT: The Free Gaza Movement is a Cyprus-registered charity. Created on the initiative of six Americans in 2006, it now has a worldwide membership with a core group estimated at 200.

WHY: The group says its key mission is to break Israel’s closure of Gaza, a strip of coastal desert territory blockaded since 2007. “Israel has no right to imprison 1.5 million Palestinians,” says Greta Berlin, a spokeswoman for the movement and a founder member. “If governments won’t do the job, civil society will.”

PAST MISSIONS: The movement has organized nine seaborne aid missions to Gaza since August 2008, four of which were allowed to reach their destination. The flotilla intercepted on May 31 was by far the largest of the nine. Other boats turned away by the Israeli navy included one damaged in a collision with an Israeli naval vessel in December 2008, which limped into the Lebanese port of Tripoli. In June 2009 Israel arrested 21 activists sailing to Gaza from Cyprus and confiscated their vessel after they ignored warnings to stop.

The Movement has not used Cyprus as an embarkation point since last year, and Cyprus closed its ports to the latest flotilla, citing reasons of national interest.

FUNDING: The Movement says it gets donations from citizens around the world. The largest donation so far was 300,000 euros ($366,000) from the Perdana Global Peace Organization in Malaysia. It says it does not receive funding from governments.

Compiled by Michele Kambas, editing by Tim Pearce