MOSCOW (AP) — Chechnya's Kremlin-backed leader said Wednesday that his forces have killed six suspected militants, including a warlord accused of organizing a 2011 suicide attack at a Moscow airport.

Ramzan Kadyrov, the regional leader of Chechnya, said that troops under his command had tracked down the suspects in the village of Katar-Yurt and killed all of them on the spot. Kadyrov claimed that the raid marked the elimination of the last group of militants that remained in the region.

Kremlin spokesman Dmitry Peskov said that Russian President Vladimir Putin called to congratulate Kadyrov, who personally took part in the security sweep.

Kadyrov said that those killed included warlord Aslan Byutukayev, whom Russian authorities accused of involvement in the January 2011 suicide bombing at the arrivals area of Moscow's Domodedovo airport that killed 37. Byutukayev appeared in a video alongside top Chechen warlord Doku Umarov and the suicide bomber.

Umarov, who also claimed responsibility for several other attacks in Russia, was killed in a security raid in 2013.

After Umarov's death, Byutukayev became the leader of militants in Chechnya and swore allegiance to the Islamic State group.

The Kremlin has relied on Kadyrov to stabilize Chechnya after two separatist wars in the 1990s and the early 2000s and has provided generous subsidies to help rebuild the region.

International human rights groups have accused Kadyrov of rampant rights abuses, including arbitrary arrests and extrajudicial killings by his feared security forces.

Despite Kadyrov’s relentless crackdown on suspected extremists, some of whom have sworn allegiance to the Islamic State group, militants have continued to launch sporadic attacks in Chechnya and other regions in Russia’s North Caucasus.