JERUSALEM, Israel - The Israeli Navy made its first radio contact with the protest flotilla, asking them to identify themselves and warning that the Gaza Strip is a closed military zone.
The first contact took place about 11:00 p.m., according to an al-Jazeera reporter on board, as organizers warned protesters of potential violence and instructed them to put on their life vests.
The flotilla did not expect to be met so far out to sea and changed course to try to avoid a nightime confrontation with the Navy, Israel Radio reported.
The six-vessel flotilla, made up of three cargo and two passenger ships, set sail Sunday morning, several days later than planned.
Two of the ships grounded by engine malfunctions were left behind. They may try to follow in a second wave in a few days. The flotilla reportedly lost satellite phone connections more than once before setting sail.
In addition to mechanical and communication problems, the flotilla's organizers encountered a diplomatic setback when the Cypriot government would not allow its port to be used.
The organizers planned to ferry about two dozen protesters, including a group of European parliamentarians and a Holocaust survivor, to the flotilla from Cyprus.
When they were turned down, organizers enlisted the Turkish government, which facilitated arrangements through Turkish Cypriot officials on the northern side of the island.
Meanwhile on Sunday, the Israeli Foreign Ministry released a statement on anti-Semitic chants recorded from the flotilla.
"Khaibar Khaibar ya yahud, Jaish Muhammad saya'ud," meaning "Jews remember Khaibar, the army of Mohammed is returning."
The chant relates to a seventh-century Muslim massacre and expulsion of Jews from Khaibar, which is in modern-day Saudi Arabia.
Click here to view Palestinian Media Watch video of the chant.
Deputy Foreign Minister Danny Ayalon said the chants evidenced the "real motivation" of the "armada of hate."
"Israel condemns the anti-Semitic chants that were publicized this morning," Ayalon said.
"The main organizer of the flotilla is an extremist Islamic organization with ties to Hamas and global jihad, and it is unfortunate there are those who are duped into thinking this exercise has anything to do with humanitarian or human rights," he said.
Navy Awaiting the Flotilla
The Israeli Navy has been waiting for the flotilla's arrival since Friday. It has readied a large fleet to accomplish its goals with a minimum amount of force.
"Experience has shown that a large number of forces diminish the volume of violence need to carry out the mission," read a statement by the Navy.
"The mission is relatively simple, and we are aware that the other side will try to make us look bad. We will show restraint and not respond to provocations. We will only do what is necessary to carry out the mission, no more but no less either," the statement read.
The Navy is hoping the ships' captains will retreat after a series of warnings, but the protesters have been saying for days they will reach their destination one way or another.
"We fully intend to go to Gaza regardless of any intimidation or threats of violence against us," one protester said. "They are going to have to forcefully stop us."
Israel cannot allow such a precedent, which would open the port for Iranian funds and weaponry to flow freely to Hamas and other Islamic terror cells in the Gaza Strip.
Naval officers are prepared to board the ships and sail them to the Ashdod port, where passengers will disembark and be taken to tents for identification and medical attention, if needed.
An Israeli police force will be at the port to prevent provocations by the protesters.
If they are willing to leave the country voluntarily, the government will assist them. If not, they will taken into custody by the Prison Service and Interior Ministry.
The cargo will be unloaded, inspected, and transported to Gaza.
AP and The Jerusalem Post contributed to this report.