Two bloody attacks in Dagestan, in southern Russia, on Sunday ignited fears of extremist violence on the home front, as the Kremlin pours resources and bodies into its sprawling war in Ukraine.
Gunmen slaughtered at least 20 people and set fire to houses of worship, and video quickly circulated on social media of men with rifles standing in a street and shooting, including at passing vehicles. Though little else is known about the attacks, they touched a nerve in a region long strained by separatist and ethnic tensions.
Here is what we know:
What happened, and who is responsible?
Groups of gunmen launched seemingly coordinated attacks on synagogues and Orthodox churches in two cities — Makhachkala, Dagestan’s capital, and Derbent — that are more than 70 miles apart.
Though Russian officials called the violence acts of terrorism, they did not blame the attacks on any specific people or groups. No organization has claimed responsibility, and the motive remains unknown.
Russia’s Investigative Committee opened a terrorism investigation.
Before a deadly assault in March at a concert hall outside Moscow, U.S. intelligence agencies warned of a pending attack by an offshoot of the Islamic State, and after that attack, they quickly said the group was responsible.
But on Monday, American officials said they still had not made an assessment about who had committed the shootings in Dagestan.
Where is Dagestan, and who lives there?
Dagestan, one of more than 20 republics that are part of the Russian Federation, lies in and near the Caucasus Mountains, on the western shore of the Caspian Sea. Chechnya, another Russian republic, and Georgia sit to the west of Dagestan, and Azerbaijan to the south.
The region, one of Russia’s poorest, is famed for its striking, mountainous landscape. It has long been a crossroads of migration, conquest and empire, which Russia wrested away from Persia in a series of conflicts in the 18th and 19th centuries.
The majority Muslim population, about three million people, is ethnically and linguistically diverse, with some of its people speaking Turkic or Iranian languages, in addition to Russian.
What is the recent history of that region?
Since the collapse of the Soviet Union, the Caucasus has been deeply unsettled, torn by wars, separatist movements and extremism.
The bloodiest conflicts, which sometimes spilled over into Dagestan, were the wars in Chechnya, another majority Muslim region, between 1994 and 2009, which claimed tens of thousands of lives.
Russia’s brutal suppression of Chechen separatists radicalized some of the region’s Muslims, as did the wanton destruction inflicted on Syria by the Russian military fighting on behalf of President Bashar al-Assad in that country’s civil war.
In the mid-2010s, the Islamic State in Iraq and Syria capitalized on that undercurrent of extremist sympathy and recruited heavily in the Caucasus. In June 2015, a Dagestan Governorate of the Islamic Republic was coined on social media, with Russian-speaking imams threatening Russia and proclaiming the eventual spread of the caliphate to the Caucasus. Scores of people from the Caucasus region traveled to the Middle East to join what they saw as a holy war.
In October 2023, on the heels of anti-Israel protests in Dagestan, a mob that included men carrying Palestinian flags stormed a plane that landed at a Makhachkala airport from Tel Aviv, injuring 20 people. Later analysis found that a false rumor claiming Israeli refugees were resettling in Dagestan had been festering on local Telegram channels for weeks leading up to the riot.
In the 1990s, Russian-backed separatists fought against Georgia, a country that had been part of the Soviet Union, sowing the seeds of a Russian invasion in 2008. And two other former Soviet republics, Azerbaijan and Armenia, have fought repeatedly over territory.
Does Russia have a modern history of terrorist violence?
A number of major terrorist attacks have occurred in Russia since the dissolution of the Soviet Union, with Islamist extremists blamed for many of them.
A series of apartment building bombings in 1999, which Russia accused Muslims from the Caucasus of carrying out, provided the rationale for the second Chechen war. Some Russian dissidents and others have claimed that the Russian government’s own operatives committed the bombings to supply a pretext for war.
In 2002, Chechen gunmen seized a Moscow theater, taking some 750 people hostage. More than 100 captives died when security forces raided the theater and killed the hostage-takers. Two years later, Chechen militants carried out a similar attack on a school in Beslan, in the Caucasus, taking more than 1,000 people captive. Over 300 of them died when the authorities stormed the building.
People stating allegiance to groups like the Islamic State and Al Qaeda have claimed responsibility for a number of other deadly bombings and gun attacks over the past two decades.
By far the most serious occurred in March this year, when four gunmen killed 145 people at the Crocus City Hall concert venue on the outskirts of Moscow. U.S. intelligence officials said the attack had been the work of Islamic State Khorasan Province, known as ISIS-K, which is active in Pakistan and Afghanistan, and the group claimed responsibility.
The Russian government, which had brushed off U.S. warnings that such an attack was coming, blamed Ukraine and the West but offered no supporting evidence. Four men from Tajikistan, a former Soviet republic in Central Asia, were arrested and charged.
The attacks on Sunday in Dagestan could be indicative of a trend, experts say.
“There are signs that it could expand further,” said Jerome Drevon, a senior analyst of jihad and modern conflict with the International Crisis Group, especially while Kremlin intelligence resources are focused abroad.
Julian E. Barnes and Anton Troianovski contributed reporting.