Belarus has taken strong diplomatic action against Sweden following a stunt involving parachuted teddy bears.
Sweden says all of its diplomats have been expelled from Belarus, which has also closed its embassy in Stockholm.
Belarus was angered when a Swedish public relations firm dropped about 800 teddy bears with pro-democracy messages from a light aircraft.
President Alexander Lukashenko sacked his air defence chief and head of border guards over the 4 July incident.
He told their replacements not to hesitate to use force to stop any future air intrusions from abroad.
On Tuesday Belarus's KGB state security service said two Belarusian men, Anton Suryapin and Sergei Basharimov, had been detained on suspicion of complicity in "illegal intrusion".
The Organisation for Security and Co-operation in Europe said Mr Suryapin, who runs the Belarusian News Photos website, had merely uploaded photos of the teddy bears.
The OSCE's spokeswoman on freedom of the media, Dunja Mijatovic, said she was "surprised and alarmed" at the charges.
"I hope that he will soon be set free and cleared of all charges brought against him," she said.
"I further hope that the 'teddy bear case' is not the latest attempt to suppress freedom of expression in Belarus using dubious criminal charges."
Belarus expelled Sweden's ambassador on 3 August, and withdrew its own envoy to Stockholm. Sweden's ambassador had apparently angered Minsk by holding meetings with the Belarusian opposition.
Sweden then said it would not allow a new Belarusian ambassador to take up his post, and asked a further two Belarusian diplomats to leave.
After Belarus announced further action on Wednesday, Swedish Foreign Minister Carl Bildt said in a Twitter comment that Mr Lukashenko's "fear of human rights [is] reaching new heights".