A police spokesperson confirmed an arson investigation but said there was currently no evidence that the attack specifically targeted Rohde & Schwarz, the Reuters news agency reported.
A 28-year-old woman and a 38-year-old man, both Bulgarian nationals, were arrested in connection with the incident, according to Reuters.
The fire caused no significant damage and was quickly extinguished. No one was injured, police said.
Rohde & Schwarz confirmed that an incident occurred at a construction site near its headquarters, Reuters reported.
German authorities are on high alert for attacks on infrastructure after the government said this week that Russia was behind an attempted drone attack on a Ukrainian cargo plane at Leipzig/Halle Airport last month.
German Interior Minister Alexander Dobrindt has said foreign powers, particularly Russia, could be using left-wing extremist groups as proxies for sabotage. He warned that some of those groups increasingly echo Russian narratives about the war in Ukraine, Reuters reported.
Poland on Wednesday expressed solidarity with Germany in opposing what it described as Russian "acts of sabotage" and "terrorist activities."
European Union foreign policy chief Kaja Kallas said on Wednesday that the Leipzig attack bore all the hallmarks of state-sponsored terrorism.
German police are also investigating a suspected act of sabotage targeting power substation infrastructure near the western city of Bergheim on Tuesday and a separate incident on Wednesday in which an unknown object exploded near a train station in the southern city of Augsburg.
In another incident in Germany this week, explosive and incendiary devices damaged power lines on Tuesday near the Jänschwalde coal-fired power plant in the eastern state of Brandenburg, near the Polish border.
(gs)
Source: IAR/PAP, Reuters, gov.pl