Serbian police have detained at least 38 people who participated in protests following the controversial parliamentary and local councils' elections held on December 17. The opposition group Serbia Against Violence has been staging demonstrations, alleging election fraud, particularly in the capital city of Belgrade. International monitors have also criticized the election, stating that it was conducted under unjust conditions.

Since the elections, Serbia Against Violence has been accusing the governing populists of rigging the vote. In response, some opposition politicians have resorted to hunger strikes to protest against the alleged irregularities. On Sunday evening, protesters attempted to enter Belgrade city hall, resulting in clashes with riot police who used tear gas, pepper spray, and batons to disperse the crowd.

The protests continued on Monday evening, with hundreds of people gathering outside the state election commission in central Belgrade. They then marched towards city police headquarters, where it is believed that opposition supporters who were detained are being held. The detained individuals are facing charges of inciting violent change to the constitutional order and engaging in violent behavior.

Meanwhile, Serbia Against Violence has announced that they will not recognize the election results and are calling for the vote to be annulled. The alliance has called upon the European Union (EU) to investigate the election results. Concerns over transparency and fairness have been raised by international observers, adding fuel to the opposition's claims.

The US ambassador to Serbia, Christopher Hill, condemned the violence and vandalism that occurred during Sunday's protest. He emphasized the importance of transparency in democratic processes and the need for all parties, regardless of the outcome, to respect the will of the people.

Senior police official Ivica Ivkovic confirmed that eight officers were injured during the clashes, some seriously. The opposition has accused the police of using excessive force and physically assaulting their supporters.

In a separate incident on Monday, several hundred university students and citizens blocked a key street near the government headquarters in Belgrade, despite police warnings against such blockades. No incidents were reported, and some students even engaged in friendly games of volleyball and soccer.

The Serbian Progressive party, which emerged as the winner in the election, has denied allegations of vote rigging and insisted that the ballots were fair. However, international observers and local election observers have reported multiple irregularities, including cases of bought votes and ballot-box stuffing. They have also highlighted media bias, abuse of public resources by the ruling party, and the dominance of President Aleksandar Vučić in the campaign, despite not being a candidate himself.

Serbian President Vučić has suggested that Sunday's protests aimed to overthrow the government with foreign assistance, without providing further details. On Monday, the Russian ambassador, Aleksandr Botsan-Kharchenko, claimed that Vučić had "irrefutable evidence" of Western involvement in encouraging the opposition protests.

The situation remains tense as the opposition continues to demand a thorough investigation into the election and calls for a new vote under transparent and fair conditions. The Serbian government, on the other hand, appears determined to maintain stability and has warned that they are prepared to counter any acts of violence.