Belarus has expelled Sweden's ambassador after a Swedish public relations firm dropped 800 teddybears near the capital, Minsk, in a pro-democracy stunt last month.
The incident on 4 July had already prompted President Alexander Lukashenko to sack two generals - the head of the air force and the head of border security.
Swedish foreign minister Carl Bildt says the Lukashenko regime has made groundless accusations against the ambassador, Stefan Eriksson.
Mr Bildt says Belarus had quoted Mr Eriksson's meetings with the opposition as one reason for expelling him. Another reason was donating books on human rights to a university library in Minsk.
''Fundamentally, this is about Sweden being engaged in democracy and human rights in Belarus," Mr Bildt says.
He said Belarus's incoming ambassador to Sweden will not be welcome and two other Belarussian diplomats in Sweden have been asked to leave.
Mr Lukashenko ordered border guards on Thursday not to hesitate to use weapons to stop any future air intrusions from abroad.