MINSK (Reuters) - Authorities in Belarus arrested and fined two journalists for posing for photographs holding teddy bears after hundreds were dropped by air on the country in a pro-democracy stunt, the Belarussian Association of Journalists said on Thursday.

Alexander Lukashenko, the authoritarian president, also suggested on Thursday that the Swedish embassy in Minsk had been involved in planning the July 4 escapade, in an outburst likely to widen a diplomatic rift with Sweden over the incident.

"Those who came and prepared the violation of the state border worked together with the (Swedish) embassy. We have proof of this," Lukashenko was quoted as saying by the Belarus state news agency Belta.

The journalists' arrest and Lukashenko's accusation underlined the depth of his anger and embarrassment over the stunt and his determination to punish those he views as being responsible for it.

The two journalists, Irina Kozlik, who works for Komsomolskaya Pravda newspaper, and Yulia Doroshkevich, a press photographer, were each fined 3 million Belarussian roubles (about $400) at separate court hearings in Minsk and released.

An official for the ex-Soviet republic's journalist association said that Kozlik, 27, and Doroshkevich, 31, were detained on Wednesday evening in the capital Minsk.

The two women were accused of "carrying out an unsanctioned protest," Andrei Bastunets, deputy head of the association, told Reuters.

The July 4 stunt, in which a light aircraft chartered by a Swedish PR firm Studio Total dropped 800 toy bears carrying pro-democracy messages over Belarussian territory, prompted Lukashenko to sack his air defense and border guards chiefs and expel Sweden's ambassador.

The teddy bear "blitz" was the latest pro-democracy stunt aimed at mocking Lukashenko's iron grip on a country he has ruled since 1994, three years after the Soviet Union's break-up.

Once described as Europe's last dictator by the U.S. administration of George W. Bush, Lukashenko has been ostracized by the European Union and United States over a harsh crackdown on opponents who challenged his re-election in December 2010.

Last summer, opposition groups staged waves of "silent" protests in Minsk in which people engaged in synchronized public clapping and coordinated their mobile phones to ring out in unison to show their disapproval of Lukashenko's style of rule.

DIPLOMATIC RIFT

With both Belarus and Sweden now pulling all their diplomats out of each other's country, the diplomatic rift has worsened Belarus's already poor relations with the West.

In comments issued by Belta news agency on Thursday, Lukashenko said Belarus still awaited an answer from Sweden and neighboring Lithuania about their role in the airdrop. The plane entered Belarussian air space from Lithuania.

"If these answers do not come according to international norms, we will find an adequate response ourselves ...," he said.

"Lithuania shouldn't sit like mice under the broom either. They have got to say why they allocated their territory for violating a state border," he added.

In a statement on Thursday, the U.S. State Department said the expulsion of the Swedish diplomats only served "to deepen Belarus' self-isolation ... We again call on Belarus to immediately release and rehabilitate all political prisoners, and to put an end to the repression of civil society and the democratic opposition."

It took more than three weeks for Belarus to formally confirm the teddy bear airdrop. It was all the more embarrassing for Lukashenko and his defense chiefs since the incident occurred a day after Independence Day, which also commemorates Minsk's World War Two defense against Nazi Germany.

Lukashenko sacked two generals, including the head of the air defenses, and told the incoming border guards chief to use weapons if necessary to shoot down any future foreign intruders into Belarussian air space.

Belarus's KGB state security agency has since charged two Belarussians, Anton Suryapin and Sergei Basharimov, with complicity in the "illegal intrusion" by the Swedish plane.

Suryapin, who is aged about 20, had earlier been identified as a blogger who was arrested after the first photographs of the toy bears were published on the Internet. In the past week, some Belarussian journalists have shown solidarity with Suryapin by posing for photos on the Internet holding miniature toy bears.

(Writing By Richard Balmforth; Editing by Rosalind Russell)