Families of those killed aboard an aid flotilla to Gaza in 2010 will appeal the International Criminal Court's decision not to press charges against Israel, their lawyers announced on Thursday.
The ICC's chief prosecutor Fatou Bensouda said Monday there was "no reasonable basis to proceed with an investigation".
Nine Turkish citizens lost their lives when Israeli commandos stormed the Mavi Marmara ship, which was trying to breach the embargo on Gaza and deliver humanitarian aid.
One more died in hospital in 2014.
The ICC's decision shows the "intent is to safeguard Israel -- so blatantly and flagrantly right under the international community's nose -- against any indictments of war crimes," the families' lawyers said in a joint statement.
"We expect the High Court to accept our appeal and initiate the investigation by overturning the prosecutor's decision," they added.
The ICC prosecutor's decision came three months after the tribunal's judges in The Hague ordered her for a second time to reconsider investigating the case.
The legal process was triggered in May 2013 by the Comoros, the Indian Ocean nation where the ship was registered.
The prosecutor's office said in 2014 that the case was "not of sufficient gravity" to come before the international court.
The families' lawyers said it was not an isolated problem and that the prosecutor's office "wilfully refuses" to open investigations involving Palestinian causes.