(Adds comment from Hamas)
By Daren Butler and Ayla Jean Yackley
ISTANBUL, Aug 11 (Reuters) - A Turkish pro-Palestinian group plans to send aid ships to Gaza to challenge the Israeli blockade, it said on Monday, four years after Israeli commandos stormed its flotilla bound for the territory, killing 10 Turks.
The plan may hinder efforts to rebuild shattered diplomatic ties between Turkey and Israel, just as Ankara launched an "air corridor" carrying wounded Palestinians to Turkey and aid to Gaza.
The Humanitarian Relief Foundation (IHH) announced that activists from 12 countries had decided to launch a convoy of boats to Gaza "in the shadow of the latest Israeli aggression.
"The Freedom Flotilla Coalition affirmed that, as most governments are complicit, the responsibility falls on civil society to challenge the Israeli blockade on Gaza," it said in a statement after the group met in Istanbul at the weekend.
An IHH spokeswoman did not elaborate but said the group would hold a news conference on Tuesday. Turkish Foreign Ministry officials had no immediate comment.
Nine Turks were killed in May 2010 in international waters when Israeli soldiers raided their vessel, the Mavi Marmara, leading a flotilla to break Israel's blockade of Gaza. A 10th Turkish activist died in May from wounds suffered in the attack.
Turkey's relationship with its former ally Israel had been tense since late 2008 over a previous Israeli military operation in Gaza.
Prime Minister Tayyip Erdogan, who was elected president on Sunday, has been among the most vocal critics of Israel's conflict with the Islamist Hamas movement that rules Gaza.
In his election campaigning, Erdogan likened Israel's actions to those of Adolf Hitler and warned it would "drown in the blood it sheds".
Hamas spokesman Ehab al-Ghsain said: "We hope that now with the presence of Mr. Erdogan as the president, chosen by the majority of the Turkish people, the support of Turkey and their defence of our people will increase."
Israel, which denounced Erdogan's comments, says its offensive is intended to stop rocket fire from Gaza and to destroy tunnels used by gunmen to infiltrate Israel.
Pro-Palestinian sentiment runs high in mostly Muslim Turkey, and protesters have repeatedly taken to the streets in recent weeks to demonstrate against Israel's offensive in Gaza.
Three Palestinian women and a male youth were flown from Tel Aviv to Ankara overnight for medical treatment after Turkey held talks on the matter with Israel, the first step of Ankara's bid to evacuate possibly thousands from the Gaza Strip.
Foreign Minister Ahmet Davutoglu revealed details of the aid initiative last week after a month of bloodshed that has killed 1,910 Palestinians and 67 Israelis.
Osama Al-Najar, spokesman of the health ministry in Ramallah in the occupied West Bank, said 60 more wounded people would be flown to Turkey on Monday. He said the Palestinian Authority had helped organise their transfer from Gaza to Israel.
Davutoglu said Turkey planned to bring in some 200 wounded in the first stage. Health Minister Mehmet Muezzinoglu said Ankara was ready to send a 60-strong medical team to establish a field hospital in the region if permission is granted.
Turkey's state disaster and emergency authority was to send an initial aid cargo of 3,500 food parcels by plane from Ankara to Tel Aviv's Ben Gurion airport on Monday evening as part of the air corridor. (Additional reporting by Nidal al-Mughrabi; Writing by Daren Butler; Editing by Robin Pomeroy)