Serbian police detained 49 people, including officials from ministries and state-owned firms, on suspicion of corruption and abuse of office on Friday as part of an anti-graft drive that has gained momentum before this month's election.
Officials of the finance ministry, tax administration, the EPS power utility, the Putevi Srbije road maintenance company, the Post Office and 12 police officers were among those arrested across the country, Interior Minister Nebojsa Stefanovic said in a statement.
"This is yet another demonstration that the police will not stop ... Together with prosecutors, we will show Serbia can be a completely serious, honest and fair country," the statement said.
Two more suspects remain at large. The ministry alleged that the group's activities had cost the budgets of the country and the northern Vojvodina province around 7.6 million euros ($8.6 million) since 2007.
It is the second big crackdown on corruption since March when police arrested 46 people in a similar sweep.
Prime Minister Aleksandar Vucic's Progressive Party aims to cement its grip on power in the April 24 election to pursue economic reforms with the aim of completing European Union negotiations by 2019.
To join the EU, Serbia will have to step up the fight against corruption and organised crime which flourished during the wars of federal Yugoslavia's break-up in the 1990s.