BEIRUT — Tensions between Russia and Israel reignited Sunday after Russia’s Defense Ministry issued a harsh critique of Israel’s role in the downing of a Russian plane in Syria last week, despite previous efforts to smooth over the rift.

Releasing the results of an inquiry into the incident, in which a Russian IL-20 plane was shot down Sept. 17 by a Syrian anti­aircraft missile during an Israeli airstrike, Russian Defense Ministry spokesman Gen. Igor Konashenkov said the actions of Israeli fighter pilots showed “a lack of professionalism, or, at a minimum, criminal negligence.”

Fifteen Russian service members were killed on board the plane, one of the highest tolls in a single incident for regular Russian troops since Russia’s military intervention in Syria three years ago.

By failing to give adequate warning of its intention to strike in the area, in the vicinity of Russia’s main Hmeimim military base in Syria, Israel violated Russian-Israeli agreements intended to deconflict their air operations in Syria, Konashenkov said. He said an Israeli jet had used the Russian plane as cover, thereby exposing it to Syria’s antiaircraft fire.

Konashenkov called Israel’s behavior “highly ungrateful” in light of the measures Russia has taken in Syria to accommodate Israeli demands, including, he said, relocating Iranian troops from the border of the Israeli-occupied Golan Heights and providing Russian patrols in the area.

Israel responded with a statement disputing the Russian findings, saying that it had already presented Russia with a detailed account of the incident that demonstrated that Israel had acted within the boundaries of Russian-Israeli agreements.

Israel also claimed last week that its jets had returned to Israeli airspace when the missiles were launched.

The Israeli statement added it would continue to strike when it chooses in Syria to counter what it called “Iran’s incessant attempts to establish itself in Syria and to arm the terrorist organization Hezbollah with lethal and accurate weapons.” Israel would also continue to take “all necessary measures” to ensure the safety and well-being of Russia’s troops, it said.

The criticisms from Russia on Sunday were in contrast to an assessment last week by President Vladimir Putin that the shooting of the plane was attributable to a “chain of tragic accidental circumstances” and not to any missteps by Israel. In seeking to tamp down the tensions, he had signaled that Russia’s ties with Israel are too important to put in jeopardy, despite the deaths of the soldiers.

The Defense Ministry’s reiteration of the allegations that Israel was culpable raised new questions over the endurance of their understanding, according to which Russia has tolerated multiple Israeli airstrikes against targets in Syria alleged to be tied to Iran and Lebanon’s Hezbollah militia, despite Moscow’s close alliance with Damascus and Tehran.

Russia gave no indication that it is planning to take any action against Israel. But Moscow’s pushback against Israel’s version of events appeared to catch Israel by surprise, after the matter seemed to have been settled last week, and raised the question of whether Russia might seek to curtail Israel’s freedom to maneuver in Syria in the future.

The incident has also put the Kremlin in a tough spot. Acknowledging Syrian responsibility for the deaths of 15 Russian service members would cast an unflattering light on Russia’s alliance with Syrian President Bashar al-Assad, amid domestic political challenges for Putin and unease in the Russian public over Moscow’s engagement in Syria.

Blaming Israel, on the other hand, also carries risks. Putin has cast Israel as a key partner, and Russian officials point to his close relationship with Israeli Prime Minister Benjamin Netanyahu as a prime example of growing Russian influence in the Middle East.

Troianovski reported from Moscow and Eglash from Jerusalem.