DUBLIN, Aug 30 (Reuters) - Pro-Palestinian groups in Ireland launched a fundraising drive on Monday to buy a ship for a second attempt to breach Israel's sea blockade of Gaza.

The Irish Ship to Gaza campaign aims to send between 30 and 50 Irish people, including public figures, journalists and activists, to join a flotilla taking aid to people in the Hamas-controlled Gaza Strip.

Preparations are well under way internationally for the Second Freedom Flotilla, which is being assembled by the same groups that organised the Freedom Flotilla in late May, organisers said in a statement.

Between 10 and 15 ships are expected to take part, cargo ships as well as passenger vessels.

Israeli commandos killed nine pro-Palestinian Turkish activists in a melee after they boarded a vessel in the previous flotilla, which also included Irish activists. Israel and the United Nations are holding separate investigations into the incident.

In response to Western criticism, including from its biggest ally the United States, Israel has since eased a land blockade of Gaza where 1.5 million Palestinians live, allowing some civilian goods through, while continuing to enforce its naval embargo of the coastal territory.

Israeli leaders have said their troops, on boarding the Turkish-flagged Mavi Marmara, opened fire in self-defence after being set upon by activists wielding cudgels and knives.

Turkey, once Israel's close strategic ally, called the bloodshed Israeli state terrorism, withdrew its ambassador from Israel and cancelled joint military exercises.