Cyprus stopped two boats planning to carry aid to the Gaza Strip in defiance of an Israeli blockade from leaving port on Thursday, officials said.

The US based Free Gaza Movement had been planning to take 33 activists to Gaza with medical supplies and cement, a building material that Israel does not allow into the Palestinian territory devastated by a short war that ended early this year.

The Free Gaza Movement started sending regular aid voyages from Cyprus to Gaza in August 2008, but one of its boats was involved in a collision with an Israeli vessel in December, and was turned back on another mission in January.

Cypriot shipping officials cited inspection requirements for stopping the two vessels, a small ferry and a sailing boat, from leaving port two hours before their scheduled departure.
Both vessels had travelled to Gaza before.

"One of the ships was only recently registered in Cyprus and under Cyprus law it has to undergo inspection before being given permission to sail," said Serghios Serghiou, head of Cyprus’s Department of Merchant Shipping. "(The second) ... did not apply for any inspections before sailing."
Israel tightened a blockade on Gaza in 2007 after the Islamist group Hamas took control of the enclave, a tiny sliver of territory home to some 1.5m people.

Israel bans imports of cement, steel or other building supplies to Gaza, saying militants could use them for military purposes. One of the vessels was to carry 15t of cement.