Serbia was in disbelief Friday after at least eight people were killed and 14 others injured in the country's second mass shooting this week.
One suspect has so far been arrested following an hourslong manhunt throughout the night, the police said.
Hours earlier, near Mladenovac – about 60 kilometers (37 miles) south of the capital – a 21-year-old gunman armed with an automatic weapon opened fire from a moving vehicle before fleeing, state-run RTS television reported.
The shooting spree spread across three separate villages in the area, according to the state media outlet.
The shooting prompted a manhunt through the night as police combed the woods near the capital Belgrade. An Agence France-Presse (AFP) photographer saw a helicopter circling overhead with a spotlight appearing to search for the fugitive gunman.
"Following a wide search police arrested U.B.," police said in a statement, using only the suspect's initials.
"He is suspected to have killed 8 and injured 14 people overnight. The injured are hospitalized."
RTS said the man had been arrested near Kragujevac, a city in central Serbia.
The incident comes on the heels of the worst school shooting in Serbia's recent history, after a 13-year-old killed nine people, including eight fellow students, at a school in downtown Belgrade on Wednesday.
The back-to-back mass shootings have left the country in a state of shock, with thousands flocking to makeshift memorial sites while others have queued to donate blood.
As the sun began to rise early Friday, there was a heavy police presence in the region of the latest shooting.
Roughly 600 police personnel had been deployed to the area, according to RTS, with members of an elite anti-terrorist unit patrolling the highway.
The road leading to the villages of Malo Orasje and Dubona had also been sealed by authorities.
Worried relatives gathered outside the emergency medical center in Belgrade, where at least eight of the injured were hospitalized, N1 television reported.
Health Minister Danica Grujicic briefly visited the center.
Interior Minister Bratislav Gasic called the shooting a "terrorist act," RTS reported.
Serbia is set to begin a three-day mourning period Friday, during what is normally a festive time with people flocking outdoors and filling cafes to meet with friends and families.
Mass school shootings are extremely rare in Serbia and President Aleksandar Vucic called Wednesday's tragedy "one of the most difficult days" in recent history.
In a national address after the school shooting, Vucic proposed stricter gun control measures, including a two-year moratorium on issuing permits for firearms.
The Interior Ministry has appealed to all firearm owners to keep their guns locked in safes – warning those who do not abide will have their weapons seized.
Gun ownership is relatively high in Serbia, where shooting ranges are popular but special permits are required to possess firearms.
The wars in the Balkans during the 1990s amid the bloody breakup of Yugoslavia also saw a large number of weapons circulate in the region.
The Vladislav Ribnikar elementary school remained closed off Thursday, with police guarding the entrance to the building.
Large crowds of mourners continued to flock to the school to pay their respects, placing flowers, toys and candles along the pavement.
On Thursday evening, people in the Croatian capital Zagreb and the Bosnian Serb administrative capital Banja Luka also lit candles and laid flowers for the victims.
Masses for the victims were held in Belgrade churches while the head of the Serbian Orthodox Church, Patriarch Porfirije, called the shooting a "catastrophe, the likes of which has never happened in our nation and our homeland".
In the last mass shooting in the Mladenovac area, a villager killed 13 relatives and neighbors in April 2013.
