An arson attack on a suburban Athens building that houses the offices of a Greek radio station and newspaper caused significant damage early Wednesday and drew condemnation from political leaders in Greece and elsewhere in the European Union.

Explosions were heard before a fire broke out shortly after 3 a.m. at the building that houses radio station Real FM and the Real News newspaper in Maroussi, a northern Athens suburb.

Firefighters extinguished the blaze. Fire Service investigators found the remnants of three gas canisters tied together on an external stairwell between the ground and first floors, as well as a can containing a flammable liquid.

No one was injured, although a radio station sound engineer was evacuated and treated for smoke inhalation. The offices of a shipping company on the building’s top floor suffered the most damage. The newspaper in located on the first floor and the radio station on the second.

Real Group owner Nikos Chatzinikolaou, a veteran journalist, posted a short clip from his car that showed the top of the building on fire and tweeted: “Explosions and fire at Real FM and Realnews! They are burning us! They are trying to shut us down!”

Chatzinikolaou founded the media company in 2007. The group also includes news site enikos.gr.

Real Group reported on its website that security cameras showed two people with their heads covered placing the canisters and can.

Police said they suspect other people might have helped the arsonists escape, are examining security cameras from nearby buildings.

The group’s news site said a serious malfunction in the radio station’s broadcast tower on Tuesday could be related to the fire.

No one had claimed responsibility as of Wednesday afternoon.

Greece has seen similar attacks on media outlets and other targets that most often turned out to be the work of far-left groups, but Tuesday’s fire caused more serious damage.

“The freedom of the press is neither constrained nor muzzled by terrorist acts,” Greek Prime Minister Kyriakos Mitsotakis said during a Parliament session.

Opposition leader Alexis Tsipras, several government ministers and politicians from all of the countries political parties made online and live statements strongly denouncing the attack.

European Commission Vice President for Values and Transparency Vera Jourov joined the condemnation and said Greek authorities must do “much more … to guarantee the security of journalists and media, because this this attack is really shocking.”