Two Albanian soldiers were injured while trying to stop two Russians and a Ukrainian national from entering a military plant, the country's defence ministry said late Saturday evening.
One of the suspects allegedly attacked the guards while trying to take photographs of the Gramsh factory in central Albania, which is used for dismantling derelict weapons, the ministry said in a statement.
"In an attempt to escape control, one of the Russian nationals, identified by the initials M.Z., 24, used neuroparalysing spray on the two security guards," the ministry added.
Two other suspects -- a Russian citizen identified as S.T., 33, and Ukrainian national F.A., 25 -- were also arrested near the factory.
The two injured Albanian soldiers were taken to a Tirana hospital after sustaining eye injuries, statement said.
Albanian Prime Minister Edi Rama said the three individuals were "suspected of espionage".
The military police, alonside intelligence and anti-terrorism agencies, rushed to the scene to investigate the incident.
Albania has been a NATO member since 2009.
Senior Ukrainian intelligence official found dead
A regional head of Ukraine's SBU intelligence services has been found dead at his home in central Ukraine, the prosecutor general's office said on Sunday.
Oleksandr Nakonechny was found by his wife with gunshot wounds in a room of their apartment in the city of Kropyvnytsky late Saturday after she heard gunfire, the office wrote on Telegram.
Police have opened an investigation into the death, but made no further comments.
A local politician, Andrii Lavrus, wrote on Telegram that Nakonechny had shot himself. The information could not be immediately confirmed.
Nakonechny has headed the SBU in the Kirovograd region since January 2021.
In July Ukrainian President Volodymyr Zelensky fired the head of the SBU, his childhood friend Ivan Bakanov, saying he did not do enough to rid the agency of spies and Russian collaborators.
Zelensky said there would be a revision of SBU personnel and several senior officials at the agency have been fired over the past several months.