Russian security forces on Saturday killed a heavily armed gunman who broke into a private house in the suburbs of Moscow and fired at them, reportedly threatening to march on the Kremlin.

The assailant was spotted by guards after he had broken into an unoccupied house located in an elite cottage village in the Istra region, about 45km (less than 30 miles) west of Moscow. He held them at gunpoint, but they managed to escape, according to the Russian media.

For several hours, the authorities negotiated with the attacker who was in combat fatigues and toted a Kalashnikov rifle. The man claimed he came from the front lines in Ukraine and was driven by God to march on the Kremlin, the seat of the government in Moscow.

He refused to surrender, fired at the special forces and was killed when they stormed the house, Russia’s National Guard said. It said that the attacker had several automatic weapons and hand grenades.

Russian politician Alexander Khinshtein identified the assailant as Vyacheslav Chernenko, a 35-year-old resident of the Siberian city of Krasnoyarsk. It was not immediately clear if he indeed fought in Ukraine as he claimed.

Istra administrator Tatiana Vitusheva described the attacker as mentally unstable.

Some Russian media claimed that the cottage he broke into once belonged to Viktor Yanukovich, the former Moscow-friendly president of Ukraine who was driven from office by mass protests and offered shelter by Russia. It has been put up for sale by its current owner, who was abroad when the incident happened.

The incident attracted close media attention, coming nearly a month after mercenary chief Yevgeny Prigozhin launched a short-lived mutiny that saw his Wagner troops capture military headquarters in the southern city of Rostov-on-Don and then drive as close as 200km (125 miles) to Moscow in a bid to oust the country’s top military leaders.

Prigozhin agreed to end the June 23-24 rebellion under a deal that offered amnesty to him and his mercenaries and allowed them to move to Belarus.