JERUSALEM – Turkey expelled Israel’s ambassador Friday and downgraded ties to the lowest possible level over Israel’s refusal to apologize for a raid on a Gaza-bound flotilla that killed nine people last year.

Turkey’s announcement came as details were leaked over an anticipated U.N. report on the flotilla.

The report concluded that Israel used “excessive and unreasonable” force on board the Turkish ship Mavi Marmara, leading to the deaths of nine Turkish nationals. The ship was part of a flotilla that was trying to reach Gaza and draw attention to Israel’s ongoing blockade there.

The U.N. report also condoned Israel’s blockade as a “legitimate security measure,” angering pro-Palestinian supporters, who contend that the Gaza Strip has been under siege for years.

Turkish President Abdullah Gul joined Arab leaders across the region in condemning the U.N. report. “To be frank, the report is null and void for us,” Gul said.

Turkish Foreign Minister Ahmet Davutoglu said the government was downgrading diplomatic ties with Israel and that the ambassador and other high-level diplomats would leave the country by Wednesday.

In other measures, Davutoglu said, Turkey would back flotilla victims’ families’ court actions against Israel and take steps to ensure “free navigation” in the eastern Mediterranean.

An Israeli official from the Foreign Ministry, speaking on condition of anonymity, said Israel’s actions were in accordance with international law.

“The U.N. report should clarify that Israel’s actions in Gaza are legitimate. The flotilla tried to embarrass Israel. This did not work,” he said.

International attention turned toward Gaza after the deaths on board the Mavi Marmara. Amid an international outcry, Israel loosened its blockade on Gaza and allowed a larger variety of foodstuffs into Gaza.

Relations between Turkey and Israel, however, haven’t recovered.

Several attempts to reconcile the once-strong allies were met with limited success. U.S. mediators managed to persuade Turkey to pull out of a second Gaza-bound flotilla attempt this summer, but they were unable to reach a compromise on the wording of an apology from Israel.