Pro-Palestinian activists said on Tuesday they would send ships this year to Gaza in a bid to breach the Israeli blockade, repeating an action that four years ago ended with Israeli military boarding a vessel and killing nine Turks.

The Freedom Flotilla Coalition, made up of 10 rights groups from 10 countries, did not specify when the ships would sail or how many. Israel views the Istanbul-based Humanitarian Relief Foundation (IHH), a leading participant, as a terrorist group.

"It is the responsibility of civil society to challenge this blockade ... We plan to sail to Gaza during 2014," said Ann Ighe, a Swedish spokeswoman for the coalition, after a meeting in Istanbul of pro-Palestinian activists from 10 countries.

Earlier this year, Turkish anti-terrorist police raided the offices of IHH, the main agency through which Turkey channels aid to Syria, in a move the group said was a ploy to tarnish it. The IHH denied media reports at the time that it was involved in arms shipments to al Qaeda-linked groups in Syria.

In 2010, the IHH led a flotilla of ships, including the Mavi Marmara, that was carrying humanitarian aid when it was stopped in international waters by the Israeli military.

Soldiers stormed Mavi Marmara and killed nine Turks. A 10th person died this May from wounds sustained in the attack.

The incident wrecked already-damaged relations between Israel and Turkey, once close Middle East allies.

The coalition of activists will not seek support from the Turkish government, such as a military escort, because it is a non-governmental mission "committed to non-violence", said Dror Feiler, an Israeli-born Swedish citizen who took part in the 2010 effort.

"We are ready to sacrifice our lives for freedom," said Feiler. Two other Israeli citizens joined the briefing.

The plan may hinder efforts to rebuild the Turkish-Israeli relationship, just as Ankara launched an "air corridor" carrying wounded Palestinians to Turkey and aid to Gaza.

Turkish Prime Minister Tayyip Erdogan, elected president on Sunday, has been among the most vocal critics of Israel's offensive on Gaza - fighting that has killed 1,939 Palestinians and 67 Israelis.

The group said the proposed flotilla would travel to Gaza to collect commercial goods purchased from the occupied territory.