MOSCOW — Protests in Russia's Far East swelled Saturday with an estimated 50,000 people defying the Kremlin and rallying in support of a popular regional governor charged in connection with alleged murder plots.

The protests in Khabarovsk, now in their second week, have put a damper on Moscow’s victory lap after the passage of a package of constitutional amendments that will enable President Vladimir Putin to seek two more terms in office and possibly stay in power until 2036.

Demonstrations of this size are rarely seen in Russia’s remote regions. But Khabarovsk, a city of 600,000 that borders China, had the second-lowest turnout for the July 1 plebiscite with 44.2 percent, according to Russia’s Central Election Commission.

The governor, Sergei Furgal, is a member of a main opposition group, the nationalist Liberal Democratic Party of Russia. The 50-year-old Furgal was arrested July 9, hauled into the back of a black SUV by law enforcement officials in camouflage, flown more than 5,000 miles to Moscow and then charged with ordering the killings of business executives 15 years ago.

Furgal has denied any wrongdoing, and his supporters have alleged that the case against him is politically motivated — revenge for how Furgal won the 2018 gubernatorial election in a landslide against the candidate from Putin’s ruling party, United Russia.

The local support for Furgal has been strong despite Russia’s Investigative Committee saying it has witness accounts and other “irrefutable evidence” that Furgal was “involved in organizing murders and attempted murders of” rival entrepreneurs Yevgeny Zorya, Oleg Bulatov and Alexander Smolsky in 2004 and 2005, the committee’s spokeswoman, Svetlana Petrenko, told the Interfax news agency.

“If Furgal was supposedly involved in something, why did they wait 15 years?” Liberal Democratic Party of Russia head Vladimir Zhirinovsky wrote on Twitter. “Now Furgal was arrested for good work in the region and a high rating of support from citizens.”

Though the rallies in Khabarovsk have been unauthorized, local law enforcement has made no move to disperse them. Saturday’s protest, amid unusually warm temperatures for the region, had the largest showing so far with a crowd of about 50,000, according to the Kommersant newspaper.

Those in attendance held signs asking for the governor to be returned to them and called for Furgal to be tried in Khabarovsk, not Moscow.

“Furgal became too popular from the view of the federal center, and the dossier that is kept for all representatives of the elite was taken out. This is a reminder to others of how the Kremlin will fight political disobedience,” Andrei Kolesnikov, a senior fellow and the chairman of the Russian Domestic Politics and Political Institutions Program at the Carnegie Moscow Center, wrote on Twitter.

Furgal is under pretrial arrest in Moscow until at least Sept. 9.

Asked whether the Khabarovsk demonstrations can be characterized as being anti-Putin, Kremlin spokesman Dmitry Peskov said last week, “The emotional sentiment of the population of Khabarovsk and the region is understandable, considering that the situation is quite unusual and very high profile.

“In this case, one has to understand that very serious accusations have been brought against the incumbent governor: He is accused of being involved in murder. This is a very grave crime and a very serious accusation.”