The European Union (EU) foreign policy chief, Cathrine Ashton, on Monday called for a timely enquiry into deadly attacks on Gaza aid ships, which has left more than 10 persons dead, urging Israel to allow the free flow of humanitarian aid to the Gaza Strip.

Ashton, high representative for foreign affairs and security policy, expressed her deep regret at the news of loss of life and violence and extends her sympathies to families of the dead and wounded, said a spokesperson for the EU's foreign policy chief.

Ashton demanded a full enquiry about the circumstances under which the ships were seized by Israel's navy on Monday, according to the spokesperson.

The Israeli military said Monday that more than 10 pro-Palestinian activists were killed during a raid by naval commandos halting an aid flotilla heading toward the blockaded Gaza Strip.

The high representative called for an "immediate, sustained and unconditional opening" of the crossing for the flow of humanitarian aid, commercial goods and persons to and from Gaza, the spokesperson added.