Memorials have become a regular feature of Russian life

People place flowers at a memorial outside Crocus City Hall in Moscow on Sunday. Vitaly Smolnikov/AP

Huge memorials like the the one at the Crocus City Hall have become a regular feature of life in Russia — a sign of instability and volatility inside the country.

Last year people laid flowers for Wagner mercenary leader Prigozhin who died in mysterious plane crash after leading an abortive march on Moscow.

And last month, thousands turned out to pay respects to the prominent Russian opposition leader Alexey Navalny, who died suddenly in his penal colony.

Now, thousands of Russians are mourning the victims of this latest terror attack.

Alexander Matveev, 37, told CNN that people in Russia feel insecure and worried that another attack could take place.

He said he heard Putin suggest that Ukraine may be involved and it made sense to him.

“He said they were trying to escape to Ukraine. This makes sense. They just found some halfwits who were eager for money," he said. Ukraine has strongly denied any connection.

But, Matveev added he would wait to hear what investigators find.

“There is a bit of anxiety here. We are worried if another attack will take place.”

“But Russia is strong, we won’t give up.”