AMSTERDAM, Netherlands, March 4

An Amsterdam museum said Thursday it has cut its close links to the Hermitage Museum in St. Petersburg and UNESCO warned of damage to Ukraine's cultural heritage, as international cultural institutions stepped up their condemnation of Russia's invasion of Ukraine.

The Hermitage Amsterdam said it has long distanced itself from politics in Russia under President Vladimir Putin as it built close ties with the Hermitage, giving the Amsterdam museum "access to one of the world's most famous art collections, which we could draw from" for exhibitions.

"Russia's recent attack on Ukraine makes keeping this distance no longer tenable," the Dutch museum said in a statement. "Our Board and directors have decided to cut ties with the State Hermitage Museum."

It added that it hoped to eventually be able to restore ties pending peace and "changes in the future of Russia."

In another move to culturally isolate Moscow, the Swedish Academy that hands out the coveted Nobel Prize in Literature broke a long-standing practice not to make political statements and condemned the invasion.

In a statement, the academy noted that its history and mission are deeply rooted in the traditions of freedom of expression, belief and inquiry.

"We therefore join the legion of our fellow academies, literary and cultural institutions, places of higher learning, defenders of a free press, human rights organizations and nation states in expressing our abhorrence of the Russian government's unjustified attack on Ukraine and its people," it said.

The United Nations' cultural agency, meanwhile, sounded the alarm about the damage to Ukraine's cultural patrimony in announcing it was working to assess Ukraine's educational and cultural institutions and its U.N.-designated heritage sites.

Ukraine is home to seven UNESCO World Heritage sites, including the famous St. Sophia Cathedral and related monastic buildings in the capital Kyiv. Other sites on the U.N. list are located in the western city of Lviv, the Black Sea port city of Odesa and in the second largest city of Kharkiv. All four cities have been subjected to artillery attacks and air bombardment by the invading Russian forces.

"We must safeguard this cultural heritage, as a testimony of the past but also as a vector of peace for the future," said UNESCO's director general, Audrey Azoulay.

In a statement, Azoulay said the agency is coordinating efforts with Ukrainian authorities to mark as quickly as possible key historic monuments and sites across Ukraine with an internationally recognized sign for the protection of cultural heritage in the event of armed conflict.

UNESCO will also organize a meeting with the country's museum directors to help them safeguard museum collections and cultural property as the war rages on.

At least seven educational institutions have been damaged in attacks over the past week, including the Karazin National University in Kharkiv on Wednesday, the statement said.

In the past week, Hollywood has joined international film festivals, orchestras, art exhibits and other cultural institutions in blacklisting Russia and promoting Ukrainian artists in a sign of solidarity.

Russian Ballet Theatre, an independent ballet company dedicated to that style of dance with a multinational cast that is currently on tour in the U.S., renamed itself RBT Ballet Theatre on Thursday and is using the slogan "We Dance for Peace. We stand with Ukraine."