As Russian troops approached the capital of Ukraine, more Russians spoke out against the invasion Saturday, as the official rhetoric by the government grew more harsh.

The Russian capital Moscow saw small-scale street protests resume despite massive detentions on Thursday, Friday. According to OVD Info, a rights group that tracks political arrests and estimates that at least 460 people were arrested in 34 cities for protesting war on Saturday. This includes more than 200 in Moscow.

Open letters condemned Russia’s invasion in Ukraine continued to pour in. On Saturday, more than 6,000 doctors signed one; 3,400 engineers and architects endorsed another. 500 teachers also signed a third. Since Thursday, similar letters have circulated by journalists, members of municipal councils, cultural figures, and other professional groups.

Garage, a prominent Moscow-based contemporary art museum, announced Saturday that it would stop working on exhibitions and put them on hold “until the political and human tragedy in Ukraine has ended.”

The museum stated that they could not support the illusion of normality while such events were taking place. “We consider ourselves part of a larger world that isn’t divided by war.”

A petition online to end the attack on Ukraine was launched on Thursday morning and received over 780,000 signatures Saturday evening. This makes it one of Russia’s most popular online petitions.

Some parliament members made statements decrying the invasion. They voted earlier this week to recognize the independence from two separatist areas in eastern Ukraine. This vote was done before the Russian attack. Two members of the Communist Party, which is a party that usually follows the Kremlin’s lines, condemned the hostilities via social media.

Oleg Smolin stated that he was “shocked” by the attack and that he believed that military force should only be used in politics as a last resort. Mikhail Matveyev, his fellow lawmaker, said that “the war must immediately be stopped” and that Russia should “be a shield against bombing Donbas and not Kyiv.”

The Russian authorities took a more harsh stance against those who denounced the invasion at home and abroad.

Dmitry Medvedev (the deputy head of Russia’s Security Council, which is headed by President Vladimir Putin), said that Moscow might respond to Western sanctions by opting for the U.S. nuclear arms agreement, cutting diplomatic ties and freezing assets.

He warned that Moscow could reinstate the death penalty after Russia was expelled from Europe’s top human rights group. This chilling statement shocked human rights activists in a country which has had a moratorium against capital punishment since August 1996.

Eva Merkacheva was a member the Kremlin’s human rights council. She deplored the decision as a “catastrophe” and a “return the Middle Ages.”

New restrictions were imposed by the West on Russian financial operations. A ban on technology exports to Russia was also imposed. The assets of Putin as well as his foreign minister were also frozen. The Council of Europe suspended Russian membership.

Washington and its allies believe that even more severe sanctions can be applied, including the expulsion of Russia from SWIFT, which is the dominant system for international financial transactions.

In 2008-2012, Medvedev served as a placeholder president when Putin was forced to take over the prime minister’s office due to term limits. After allowing Putin to reclaim the presidency, he served as Putin’s prime minister for eight more years.

While Medvedev was widely viewed as being more liberal than Putin during his presidency, he made threats on Saturday that even the most hawkish Kremlin figures hadn’t yet mentioned.

Medvedev observed that sanctions give the Kremlin an excuse to review its relations with the West. This suggests that Russia could opt-out of the New START nuke arms control treaty, which limits the U.S. nuclear arsenals.

Medvedev and Obama signed the treaty in 2010. It limits each country to no more that 1,550 nuclear warheads, 700 missiles, bombers, or bombers. The treaty also envisages extensive inspections on-site to ensure compliance. This pact is the last U.S.-Russian agreement on nuclear arms control. It was originally set to expire February 2021, but Washington and Moscow extended it for an additional five years.

Russia can opt out of the agreement at any time. This will remove all checks on U.S. nuclear forces and create new threats to global security.

Medvedev also suggested that diplomatic ties could be severed with Western countries. He claimed that there is no need to maintain diplomatic relations with any Western country. Medvedev also referred to Western threats to the assets of Russian individuals and companies. Medvedev said that Moscow would not hesitate to do the exact same.

Russian authorities cracked down on criticisms at home and demanded that independent news outlets remove stories about fighting in Ukraine.

Roskomnadzor Russia’s state communications watchdog charged that reports of “Russian Armed Forces firing on Ukrainian Cities” and the deaths of civilians in Ukraine were false. They demanded that outlets remove them or face severe fines and restrictions.

The watchdog announced partial restrictions on Facebook access Friday in response to Facebook’s restriction of accounts from several Kremlin-backed media.

Russian internet users experienced problems accessing Facebook or Twitter on Saturday. Both of these platforms have been a key player in promoting dissent in Russia over the past few years.