Nine people were killed and dozens wounded yesterday during a predawn Israel Defense Forces operation to board six ships sailing from Turkey to the Gaza Strip, after a battle erupted between the naval commandos and some 600 activists, mainly Turks, aboard one ship, the Marmara.

The commandos were surprised by the activists' violent response, and after seven of them - half the initial boarding party - had been wounded, they were ordered to open fire.

The IDF plans to investigate the operation's planning, including the decision to use naval commandos only rather than forces experienced in violent crowd control.

At about 10 P.M. Sunday night, a sizable portion of Israel's navy was sent out to meet the approaching flotilla. Adm. Eliezer Marom, commander of the navy, was in charge of the operation.

At 10:45 P.M., the navy made initial contact with the flotilla and urged it to turn around, warning that the ships would be boarded if they continued. The flotilla ignored the order, and at 4 A.M. yesterday, the boarding began.

According to the flotilla's organizers, the ships were still on the high seas at the time, and had not yet entered territorial waters. The IDF refused to say where the boarding took place.

The boarding party had real-time photographs of the ships from IDF helicopters hovering overhead, and a decision was made to board the Marmara with 14 commandos, some of whom rappeled from a helicopter. They carried rifles loaded with paint balls for crowd control, as well as loaded pistols, but the latter were not supposed to be used.

The violence began immediately, when the activists tied the helicopter's rappelling rope to the ship's antenna in an effort to down the chopper. Then, as each commando landed on deck, he was mobbed by activists who beat him with clubs and tried to stab him.

The first seven commandos were wounded and overcome within seconds. Efforts to suppress the mob with stun grenades failed. One soldier was flung from the upper deck to the lower and suffered a serious head injury; two others were stabbed by knife-wielding rioters; the remainder were clubbed to the ground. The rioters then seized two of the downed soldiers' pistols.

"It felt like the Ramallah lynching," one soldier said afterward. "They came to wage war. They stormed us and threw some of the fighters down a level; some of the fighters jumped into the sea for fear of being attacked again."

Additional soldiers soon joined the first seven, both from helicopters and via ladders from naval ships alongside. At that point, Marom and Col. A., who commands the naval commandos, concluded that the soldiers' lives were in danger and gave the order to open fire.

Senior IDF officers said afterward that the breaking point occurred when the mob began beating a fallen commando with iron bars, causing his comrades to fear for his life. The entire IDF chain of command subsequently backed the decision to open fire.

When the shooting began, the Marmara's captain urged the passengers to return to their cabins. But according to the soldiers, some of the passengers stayed and returned fire - apparently from both the two seized pistols and from arms that were already on board. A later search of the ship found rifle cartridges, but the rifle itself was apparently thrown overboard.

"We had planned on dealing with peace activists, not a battle," a senior naval officer said afterward. "This was not spontaneous, but premeditated violence. They said they came on a humanitarian mission, but they came to fight."

Altogether, it took the commandos about 90 minutes to subdue the ship and sail it toward Ashdod Port. The more seriously wounded - both soldiers and passengers - were evacuated by helicopter to Israeli hospitals; the lightly wounded were treated on board the Marmara and then by ambulance crews after reaching shore.

Two of the soldiers were initially defined as seriously wounded, but their condition has since stabilized and is now defined as moderate. Two others were moderately wounded and three lightly; two of the latter have already been released from hospital.

Of the passengers, about 30 were either seriously or moderately wounded.

In contrast to the Marmara, there was no resistance at all on three of the other ships and only mild resistance on the other two.

At a press conference yesterday afternoon, Defense Minister Ehud Barak said he regretted the casualties, "but responsibility for them rests entirely on the flotilla's organizers and participants."

IDF Chief of Staff Gabi Ashkenazi said he was convinced the soldiers had acted properly, charging that the flotilla "bore no relationship to humanitarian aid; there was extremist activity from the first moment."

After the ships finally arrived in Ashdod yesterday afternoon, the passengers were debarked and preparations for their deportation began.