JERUSALEM (JTA) — A drone that entered Israeli airspace over the Golan Heights last month was Russian.

Russia admitted to the July 17 infiltration, and said it was the result of “human error,” Haaretz reported Sunday, citing an unnamed senior Israeli official.

Israeli security services initially suspected Hezbollah, a Lebanon-based terrorist group, was behind the drone.

At least two Patriot missiles and an air-to-air missile fired by a fighter plane failed to intercept the drone, which returned to Syrian airspace.

Russian President Vladimir Putin sent his forces to Syria in September 2015 in support of the regime of Syrian President Bashar Assad in the country’s more than five-year civil war.

The drone incident was the first time that Israel fired on a Russian aircraft operating from Syria, according to Haaretz.

The drone incident was the main subject of a telephone conversation between Putin and Prime Minister Benjamin Netanyahu six days later, the Israeli official said.

“We maintain regular contact with the Russians regarding Syria,” Netanyahu said in a briefing with diplomatic reporters on July 31, during which he did not say whether the drone was of Russian origin. “The risks of a confrontation between the IDF and the Russian army are not small, so the coordination between us requires constant maintenance. Both I and Russian President Putin view this that way, and this coordination will continue.”

Netanyahu and Putin have met four times in the last year, and they speak by phone every few weeks, according to Haaretz.