BERLIN, March 25. /TASS/. German security agencies continue to keep in professional contact with their counterparts in Russia, German Federal Government Spokesperson Steffen Hebestreit told reporters at a briefing.

"There are still contacts with Russia at the working level," he said in response to a related question.

Hebestreit also recalled that earlier the US had openly warned about the terrorist threat in Russia.

On the evening of March 22, a terrorist attack targeted the Crocus City Hall music venue in Krasnogorsk, Moscow Region, just over the Moscow city limits. According to the Russian Investigative Committee, the current death toll is 137, but may rise. The Moscow Region Health Ministry said that 182 people were injured.

Eleven individuals suspected of being involved in the terrorist attack have been apprehended, including four gunmen who were detained in the Bryansk Region, southwest of Moscow, as they attempted to seek refuge by crossing the nearby Ukrainian border.

President Vladimir Putin said in a televised address that, according to preliminary information, the Ukrainian side had prepared "a window" in the border especially for the terrorists to cross undetected. He promised to identify and punish all those who were behind the attack on Crocus City Hall and declared March 24 a day of national mourning for the victims.