Egypt opened its border with the Gaza Strip until further notice yesterday, in a clear rebuke to Israel over Monday's raid on a humanitarian aid flotilla. As Palestinians crossed freely into Gaza, activists said they had launched another ship in an attempt to breach Israel's blockade. Amid growing international condemnation of Israel's behaviour, about 480 passengers from the first convoy are still being held, and Israel refuses to disclose information about the detainees, or those killed or injured in Monday's attack. About four dozen people were being treated in Israeli hospitals and an equal number were reported to have been expelled. The crossing point in the Gaza town of Rafah is the only point on Gaza's borders that is not fully controlled by Israel. Cairo, co-ordinating with Israel, has opened it only sparingly since Hamas, who are allied to Egypt's opposition, seized control of the enclave three years ago. The Egyptian president Hosni Mubarak's order to open the crossing came a day after the raid by Israeli commandos on the aid flotilla bound for Gaza, in which nine activists were killed. Yesterday Greta Berlin, of the Free Gaza Movement, which organised the flotilla, said another cargo boat was in Italian waters en route to Gaza. A second boat carrying about three dozen passengers is expected to join it and the ships were due to arrive in the region late this week or early next week, she said. The UN secretary general, Ban Ki-moon, urged Israel to lift its Gaza blockade, saying that if it had heeded international calls to so the raid would not have happened. The attack led to near-universal condemnation of Israel's actions. The UN Security Council "deeply regretted" it and called for an impartial investigation. An emergency session, called by Lebanon, which holds the council's rotating presidency, lasted more than 12 hours on Monday and pitted Turkey against the United States in calling for strongly worded condemnation of Israel. Israel was in damage control mode yesterday. Yuval Steinitz, the finance minister, was the latest top official to claim the country had no choice but to stop the ships. He added: "Breaking the blockade of Gaza's waters would have spurred more rockets and terror attacks against Israel," he said. In Kerem Shalom, a southern Israeli town near Rafah, Israel said it was off-loading cargo from the ships in the convoy. Hamas said it would reject the aid until all the detainees from the flotilla are released. Israel said yesterday it would prevent any future aid convoys from reaching the Gaza Strip. * With additional reporting by Agence France-Presse and Reuters