JERUSALEM — Israel on Tuesday threatened to pull out of a UN probe into its deadly flotilla raid to keep the panel from grilling its troops, as the defense minister told another inquiry the fleet was a “planned provocation.”

Israel’s army chief Lieutenant-General Gabi Ashkenazi (front) sits before testifying at a state-appointed inquiry into the Israeli naval raid on a Gaza aid flotilla, in Jerusalem, August 11, 2010. Ashkenazi acknowledged on Wednesday that his troops were not ready for the violent resistance encountered when they boarded the Gaza-bound aid ship and ended up killing nine pro-Palestinian activists. REUTERS/Gali Tibbon

The bloody raid in which Israeli commandos killed nine pro-Palestinian Turkish activists sparked international outrage and led to the partial easing of a four-year blockade of the Hamas-ruled Gaza Strip.

Prime Minister Benjamin Netanyahu, who testified before the Israeli panel on Monday, insisted there was a “discreet” agreement to exclude military personnel from the UN probe, despite an earlier denial from UN chief Ban Ki-moon.

“The prime minister said Israel would not cooperate with any commission that would ask to question soldiers,” Netanyahu spokesman Nir Hefetz told military radio.

“Before Israel gave the green light to its participation in the panel we had discreet negotiations in order to ensure that this commission would not harm the vital interests of Israel,” he added.

Ban on Monday denied he had struck an agreement with Israel that would bar the UN panel from interviewing troops involved in the operation.

The row broke out as the UN committee was due to start work, and on the second day of a series of top-level hearings by an Israeli committee looking into the raid.

Testifying before the committee in Jerusalem, Defense Minister Ehud Barak said the flotilla was a “planned provocation” and that top officials had suspected more than a month beforehand that organizers were “preparing for an armed conflict to embarrass Israel.”

He said various alternatives were discussed in the weeks leading up to the raid and that he and other senior officials had considered the possibility that the activists would attack the troops when they landed.

“We regret any loss of life,” the minister said. “But we would have lost more lives if we had behaved differently.”

Netanyahu on Monday insisted that Israel had acted in line with international law and accused Turkey of seeking a high-profile confrontation that saw activists attack its commandos with iron bars and knives.

Both men were giving sworn testimony before the so-called Tirkel Commission, a panel of five Israeli investigators and two international observers charged with examining the international legality of the raid and the Gaza blockade.

Israel has said the border restrictions and the naval blockade imposed in June 2006 after the capture of an Israeli soldier by Gaza militants are necessary to prevent Hamas from importing rockets and other weapons.

The closures, which have been largely backed by neighbouring Egypt, were tightened in June 2007 when Hamas seized power.

The bloody raid caused a diplomatic crisis between Israel and Turkey and sparked global calls for an inquiry — prompting Netanyahu’s government to set up the Tirkel Commission to look into the legality of the operation.

Panel members are not authorised to probe the decision-making process which led up to the operation, nor do they have the authority to question troops involved in storming the boats.

The results of an internal military investigation, which are to be submitted to the Tirkel Commission and the UN committee, found that mistakes were made at a “relatively senior” level but that the use of live fire was justified.

Israel says its commandos resorted to force only after thArmed forces Chief of Staff Gabi Ashkenazi was to take the stand on Wednesday and was likely to be quizzed over the operational aspects of boarding the ships.

Last week Ban named his own panel, chaired by former New Zealand prime minister Geoffrey Palmer, to look into the deadly raid. It was due to begin work on Tuesday and includes representatives from Israel and Turkey.

Israel has completely rejected a separate investigation launched by the UN Human Rights Council, which it views as hopelessly biased against the Jewish state.