International activists say they will again set sail from Cyprus to blockaded Gaza despite Israel having impounded one of their boats.

Free Gaza Group spokeswoman Greta Berlin said on Wednesday that another Gaza trip is planned for mid-August once a new boat is acquired.

The Israeli navy said on Tuesday that it commandeered the Greek-flagged ferry with 21 activists and three tons of medical aid aboard after it ignored warnings to turn back.

Israel said all passengers, including former U.S. Representative Cynthia McKinney and Nobel Peace Prize laureate Mairead Maguire, will be released.

The Group has made five boat trips to Gaza since August 2008 to challenge the Israeli blockade imposed after Hamas seized control of the territory a year earlier.