Hundreds of anti-Israel protesters stormed an airport in Russia's predominantly Muslim Dagestan region on Sunday, where a plane from Israel had just arrived, forcing security forces to close the airport and remove the demonstrators.
Twenty people were injured before forces contained the protest at Makhachkala airport, local authorities said. The passengers on the plane were safe, security forces told Reuters.
The unrest followed several other anti-Israel incidents in North Caucasus sparked by Israel's war against Hamas militants in Gaza. The Dagestani government said early on Monday that it was strengthening security measures across the republic, which is home to about 3 million people.
The unrest in the region, where Russian security forces once fought an Islamist insurgency, could pose another challenge for Russian President Vladimir Putin, who is waging a war in Ukraine and who has faced an attempted mutiny this year.
Videos from Makhachkala airport obtained by Reuters showed the protesters, mostly young men, waving Palestinian flags, breaking down glass doors and running through the airport shouting "Allahu Akbar" or "God is Greatest".
Another group were seen trying to topple over a patrol truck.
The Russian Aviation Authority closed the airport until it completes security checks. There were no immediate reports of arrests, but Russia's federal investigations agency ordered a criminal probe into the incident.
Sergei Melikov, the head of Dagestan, said the incident was a gross violation of the law, even as Dagestanis "empathise with the suffering of victims of the actions of unrighteous people and politicians, and pray for peace in Palestine".
"There is no courage in waiting as a mob for unarmed people who have not done anything forbidden," Melikov said on the Telegram messaging app.
Regional leaders in two other areas of the northern Caucasus called for calm. A similar appeal was issued by Dagestan's chief Muslim cleric, or mufti.
Israel urged Russian authorities to protect Israelis and Jews in their jurisdictions following the recent spate of violence against Israeli and Jewish targets.
In the past few days, a Jewish centre under construction in Nalchik, the capital of the nearby Russian republic of Kabardino-Balkaria, was set on fire, emergency officials said.
There were also reports on social media of small anti-Israeli gatherings over the weekend in Dagestan and across the North Caucasus in Russia's south. Reuters could not independently verify those reports.
Ukraine's President Volodymyr Zelensky blamed the events on Russia's "widespread culture of hatred toward other nations, which is propagated by state television, pundits, and authorities". There was no immediate comment from the Kremlin.
Russia has tried to maintain contact with all sides in the Israel-Hamas conflict, but has angered Israeli authorities by inviting a Hamas delegation to Moscow. Israel's foreign ministry summoned the Russian ambassador on Sunday.