The former Director of Macedonia's Administration for Security and Counterintelligence (UBK) Saso Mijalkov was actively involved in the staging of the terrorist attack in Kumanovo.
This is claimed by the Serbian daily Blic, based on information of the Serbian security services, BGNES news agency reports.
The leaders of the four biggest political parties in Macedonia have started a meeting in a bid to start a dialogue aimed at defusing the political tensions, MIA news agency reported on Thursday.
US Ambassador to Macedonia Jess Baily and the head of the EU Delegation in Skopje Aivo Orav are attending the meeting as observers.
The Macedonian opposition SDSM leader Zoran Zaev refused to participate at the reconciliation meeting between the four largest parties, which was reportedly scheduled to take place on Thursday.
According to media reports, Zaev would accept a meeting with Prime Minister Nikola Gruevski only in the presence of international mediators and representatives of the international community.
Macedonian Interior Minister Gordana Jankuloska, Transport and Communications Minister Mile Janakieski and the Director of the Administration for Security and Counterintelligence (UBK) Saso Mijalkov all resigned on Tuesday evening.
Their resignations come at a time of heightened political tensions in Macedonia.
Saturday's special operation in the town of Kumanovo has claimed the lives of 5 police officers, Macedonian Interior Minister Gordana Jankuloska has announced.
Another thirty have been wounded, with some of them taken to hospital. Some of the assaulters have been killed, but the number is not known.