The U.S. embassy in Prague on Thursday blasted a decision by the Czech Republic's justice minister not to extradite a Lebanese national to the U.S. to face weapons charges.

The move came on the same day that five Czech citizens who went missing in Lebanon in July returned home, leading to speculation that the Czech government did a deal for their release.

Prague's Municipal Court allowed the extradition of Ali Taan Fayad, also known as Ali Amin, and two citizens of Ivory Coast last year but Justice Minister Robert Pelikan has the final say and on Thursday refused to extradite them.

The three were arrested in Prague 2014 while allegedly trying to sell weapons to undercover U.S. law enforcement agents who pretended to be from a Colombian terrorist group.

"We are dismayed by the Czech government decision to release Ali Fayad and Khaled El Merebi," the embassy said in a statement.

Court spokeswoman Marketa Puci said Fayad and Ivoirian El Merebi were released from detention following the minister's decision. The minister still has to decide on the other Ivoirian.

"These men were indicted in the United States federal court for conspiring to kill officers and employees of the United States," the embassy said, adding the move harms the relations of the two allies.

"There's no justification for the release of these dangerous individuals, which deals a blow to the cooperative relationship of our two countries' law enforcement agencies," the statement said.

Pelikan said information from the spy services contributed to his decision but declined to give details. He said he talked to U.S. ambassador Andrew Shapiro about the case.

The announcement came hours after five Czech nationals missing since July boarded a Czech government plane in Beirut. They landed in Prague later Thursday.

Foreign Minister Lubomir Zaoralek denied that Fayad was released in exchange for the Czechs, saying the government doesn't do business with terrorists.

However, Defense Minister Martin Stropnicky previously linked the two cases in an interview for Thursday's edition of the Hospodarske Noviny business daily.

"Five people will return fine on condition Fayad is not extradited to the United States," Stropnicky was quoted as saying. "It is linked."

Later Thursday, Stropnicky released a statement saying it was a simplification "that cannot describe the complex nature of the case."

The case is surrounded by a lot of unanswered questions as Fayad's Czech lawyer was among the five Czechs who went missing, and their Lebanese driver was identified by Lebanese media as Fayad's close relative.

"It is necessary to investigate, why they traveled (to Lebanon)," Prime Minister Bohuslav Sobotka said.