Zmitser Fedaruk, fresh from the U.S. trip last week, was beaten by police on December 12 while participating in a peaceful protest ahead of a visit by Russian President Vladimir Putin.
Witnesses have said the acting head of the Malady (Youth) Front was knocked unconscious by police and taken away from the rally in an ambulance.
Fedaruk, speaking to RFE/RL's Belarus Service by telephone on December 13, said he believes he was singled out because of his recent meetings with the U.S. president and lawmakers.
"I think my beating was linked to my trip to America. There were many indications of that," Fedaruk said.
"I was deliberately pushed behind the OMON [special police] cordon and there, separated from the demonstrators, knocked down and beaten. And then they threw me back, saying something like, 'Take your man back, he made a nice trip to America.'"
Fedaruk and about 200 others had assembled on the eve of a visit by President Putin to protest a possible merger between Belarus and Russia. There have been reports that such a merger might be on the agenda of the talks in Minsk between Putin and Belarusian President Alyaksandr Lukashenka.
During a press briefing in Minsk on December 13, U.S. Ambassador to Belarus Karen Stewart condemned the Belarusian authorities' actions against Fedaruk and participants of other recent protests.(Watch her statement.)
"These brutal actions reverse what little progress had been made by the authorities in allowing peaceful protests. The Department of State in Washington has expressed my government's deep concern for all of these individuals, and we call on the Belarusian officials to ensure that all necessary medical care is given to those in need," Stewart said.
She said that in the continued absence of progress on the part of Belarusian authorities, "the United States prepares to take further steps against other state enterprises."
Following the Belarusian authorities' targeting of opposition supporters following the 2006 presidential election in which Lukashenka was elected to a third term in office, the United States and the European Union placed travel bans on Lukashenka and other government officials.
Fedaruk said from his hospital bed during his telephone interview with RFE/RL that he appreciates the support he has received.
"I'm very grateful to my friends in the United States who have spoken in my defense and condemned [these] actions of the regime. I was not the only victim; another young man, Zmitser, had one leg broken, and a girl, Palina, had a finger broken," Fedaruk said. "Many returned home from [the December 12] rally with bumps. I was taken to the hospital and was able to speak again normally only today."
Earlier on December 14, the U.S. State Department condemned the use of "brutal force" against protesters and accused Belarusian police of "specifically targeting" Fedaruk when they dispersed the rally, leading to his hospitalization "with serious injuries." "This incident is another in a long series of repressive acts by the Belarusian authorities against their own citizens," State Department spokesman Sean McCormack said.
The violent suppression of the demonstration also prompted an angry response from Congressman Alcee Hastings, the chairman of the U.S. government Helsinki Commission (Commission on Security and Cooperation in Europe) before which Fedaruk testified as part of a Belarusian opposition delegation visiting Washington last week.
"Unfortunately, the intimidation and abuse by [President] Alyaksandr Lukashenka's regime does not seem to be coming to an end anytime soon," Hastings said in a statement. "My colleagues and I on the Helsinki Commission are determined to stand by young Mr. Fedaruk and all those in Belarus -- young and old -- struggling for freedom, democracy, and respect for human rights."