Six people were killed when militant fighters attacked the parliament of Russia’s republic of Chechnya on Tuesday morning, Chechen leader Ramzan Kadyrov said, according to RIA Novosti.

“At around 8.45 am three militants opened fire at parliamentary security guards,” Kadyrov said, adding that two police officers and a parliamentary administrative manager had been killed.

He also said three militants were killed in the ensuing special operation, which took place after the building had been evacuated.

Investigators say 17 people, including six police officers, were injured.

A police source earlier told RIA Novosti that the attack began when a vehicle carrying terrorists drove in with cars carrying lawmakers.

He added that a suicide bomber had blown himself up while the other militants headed toward parliament.

This is the second serious terrorist incident in Chechnya in recent months. In August, a suicide squad launched a massive attack on Kadyrov’s home village of Tsentroi.

Chechnya, which saw two brutal separatist wars in the 1990s and early 2000s, has seen relative calm in recent years under Kadyrov, a former militant turned Kremlin ally whom critics have accused of human rights abuses.