Montenegro’s prosecutors said Tuesday they have issued international arrest warrants for two Russian and three Serbian nationals suspected of planning an anti-government attack during October’s parliamentary election.

The five are wanted for “setting up a criminal organisation and attempted terrorism,” a statement from the prosecutor’s office said.

A group of Serbians was arrested on the eve of Montenegro’s October 16 polling day and accused of plotting to seize parliament.

Former premier Milo Djukanovic had accused his pro-Russian opposition rivals of being behind the plot, which he said included plans for his assassination.

Leaders of the opposition Democratic Front have repeatedly denied this, claiming the case was set up by the government.

A total of 18 Serbians and two Russians are suspected of planning the attack.

According to local media the warrants for the five were issued in early December.

Media identified one of the sought Serbians as Nemanja Ristic, who appeared in a photo standing near Russian Foreign Minister Sergei Lavrov. The picture was taken on December 12 during Lavrov’s visit to Belgrade.

Montenegro’s prosecutors made the announcement a day afer Serbian Interior Minister Nebojsa Stefanovic said he did not know whether Ristic figured on an Interpol wanted list.

He said Lavrov’s safety had not been endangered at any moment.

Special prosecutor Milivoje Katnic said in November that two Russians still at large figured among the suspects, who wanted to stop Montenegro’s imminent accession to NATO.

But he said there was no evidence of Russian authorities being involved.

Earlier this month one of the suspects struck a plea bargain with the prosecutor and a court gave him a six-month suspended term.

Serbia initially questioned the timing of the arrests, but Prime Minister Aleksandar Vucic later said Belgrade had also detained people over “illegal activities”.

The Democratic Front openly calls for Montenegro to have closer ties with Russia and Serbia, and insists on a referendum on NATO membership.

Montenegro was invited to join the military alliance a year ago, but the decision is yet to be ratified by Podgorica and several member states.

Djukanovic’s Democratic Party of Socialists won the most seats in the election and cobbled together a coalition to rule.

The veteran leader remains head of the party and was succeeded as premier last month by his close ally Dusko Markovic.