Ambassadors from a number of foreign countries took part in a ceremony on Saturday in memory of the victims of this month’s concert hall attack near Moscow which left dozens dead, the Russian foreign ministry’s protocol department said.

Gunmen opened fire with automatic weapons at concertgoers on March 22 in the worst attack in Russia in two decades which left at least 144 people dead.

“On March 30, 2024, a ceremony to lay flowers at the spontaneous memorial near the Crocus City Hall complex was held. Heads and staff of more than 130 diplomatic missions (over 250 people) took part in the memorial action,” the ministry’s State Protocol Department said on its website.

Among those who took part were ambassadors from the United States, European Union, Africa, Latin America, as well as representatives of the UN and other organisations, Kommersant newspaper reported.

They and other visitors laid flowers at the memorial and launched white balloons into the sky.

“We are deeply grateful to the distinguished representatives of the diplomatic corps for their solidarity with the Russian people at such a difficult time,” the protocol department said.

Islamic State claimed responsibility for the attack and U.S. officials say they have intelligence showing it was carried out by the network’s Afghan branch, Islamic State Khorasan (ISIS-K).

Russian investigators said on Thursday they had found proof that the concert hall gunmen were linked to “Ukrainian nationalists”, an assertion dismissed by the United States as baseless propaganda.

Russia has said from the outset that it believes Ukraine was linked to the attack, even though Kyiv has denied it.