Israel has apologized for the deaths of nine pro-Palestinian Turkish activists after a naval raid on a ship bound for the Gaza Strip in 2010.

A senior Obama administration official said Israeli Prime Minister Benjamin Netanyahu expressed regret and acknowledged “operational mistakes” in a phone call with his Turkish counterpart, Recep Tayyip Erdogan. Erdogan accepted the apology, the official said.

Netanyahu also agreed to compensate the families of the victims in the incident, Reuters reported.

Another Obama administration official called it a “first step” toward normalizing relations between Israel and Turkey, which suffered a serious setback after the raid, including Turkey withdrawing its ambassador.

President Barack Obama helped arrange the call shortly before leaving Israel, the Associated Press reported. The apology had been the subject of talks during his visit to the Jewish state.

The phone call between the Israeli and Turkish leaders lasted about 30 minutes, with Obama himself getting on the call at some point.

“I welcome the call today between Prime Minister Netanyahu and Prime Minister Erdogan,” Obama said in a statement afterward. “The United States deeply values our close partnerships with both Turkey and Israel, and we attach great importance to the restoration of positive relations between them in order to advance regional peace and security. I am hopeful that today’s exchange between the two leaders will enable them to engage in deeper cooperation on this and a range of other challenges and opportunities.”

The ship, the Mavi Marmara, was part of a flotilla organized by the “Free Gaza Movement” that said it was bringing humanitarian aid to blockaded Gaza. Israeli commandos sought to block the ship from reaching Gaza and clashed with activists aboard, leaving eight Turks and one Turkish-American dead.

The raid and the deaths caused a massive international outcry largely directed at Israel, though the New York Times described activists aboard the ship as “picking a fight” by attempting to break the blockade. The Reuters news agency was also hit for editing photos to crop out a knife showing one of the activists was armed in an image of a bleeding Israeli commando.

​This post has been updated.