Two boats carrying members of a US-based activist group left Cyprus for Gaza early Friday to try and break the blockade imposed on the territory. The boats - the 70-foot Free Gaza and 60-foot Liberty - left the southern port of Larnaca about 10 a.m. (0700 GMT) for the estimated 30-hour trip. Members of the Free Gaza protest group said some 40 activists from 16 countries - including an 81-year-old Catholic nun - will attempt to break the blockade and that they hoped other rights groups will follow their example. "It's about human rights...to let Palestinians and visitors travel freely to and from Palestinian lands, what could be more basic than that?" said Free Gaza organizer Paul Larudee. The group plans to deliver 200 hearing aids to a Palestinian charity for children and hand out 5,000 balloons. Israeli officials said the delivery was illegal but they have refused to publicly say what the response would be if the activists tried to break the blockade. However, The Jerusalem Post has learned that the navy has been ordered to turn back the boats. Larudee said it was "highly unlikely" the navy would fire on the boats to stop them. But he said the group expected Israeli authorities to intercept the boats and arrest those onboard. Larudee said the group would contest any arrests in court on the premise that Israel committed kidnapping. Israel imposed the blockade after Hamas violently seized control of Gaza in June 2007, routing Fatah forces. It tightened its sanctions in response to ongoing rocket attacks by Hamas and other terror groups targeting civilians in Israeli towns near Gaza.