Police said a security guard witnessed several individuals around 2:40 a.m. local time tossing bottle-based incendiary devices at the façade of the Robert Koch Institute (RKI), located in Berlin's Tempelhof neighborhood, German broadcaster Deutsche Welle reported.

Photos showed a shattered window partially blackened from flames at the building housing the federal government agency and research institute responsible for disease control and prevention. Police are investigating whether the attack was politically motivated, according to Reuters.

Hours later, some 2,000 demonstrators gathered at Berlin's Alexanderplatz to protest new coronavirus restrictions enforced in the German capital as infection rates spiked nationwide in recent days. Police said most people in the crowd flouted social distancing and did not wear masks, according to Deutsche Welle.