The National Protection Service (NSO) has opened an inquiry into one of its officers who knocked journalist Sonya Koltukliyeva to the pavement outside the Progressive Bulgaria headquarters in Sofia. The service has also notified the military prosecutor's office.

The incident happened on the evening of 22 October, after a briefing by prime minister Rumen Radev that Koltukliyeva was covering. The guard shoved her after she opened the door of the official car of parliament speaker Mihaela Dotsova. The journalist was in the emergency department of the Military Medical Academy. A video of the incident spread on social media.

What happened before: Sonya Koltukliyeva in Military Medical Academy after incident with Dotsova's NSO guard

The NSO said it has reviewed the footage. Its leadership ordered an immediate, detailed check of how the guards acted. If their actions did not fit the situation, the strictest action will follow, the service warned. It called for respect for the inviolability of the people it protects, and said any attempt to breach it obliges officers to act in line with the law.

President Iliana Yotova strongly condemned "the unacceptable and excessive reaction of an NSO officer towards journalist Sonya Koltukliyeva".

"Such behaviour is unacceptable and cannot be justified by the performance of official duties," she said.

Yotova said journalists must be able to work freely and without fear. She expects a quick report from the inquiry, a full account of what happened and, if rules were broken, someone to take responsibility. She appealed to everyone to act responsibly, stay calm and strictly follow the law, because political passions are running high on all sides in the election campaign.

GERB leader Boyko Borisov posted the video on his Facebook page and wrote: "Shameful! This job is not for amateurs! Shove and clear away anyone who asks questions?! Resign!"

Asen Vasilev, chairman of We Continue the Change, also shared the clip on Facebook. He commented: "Total loss of self-control! On Sunday we have a chance to show them that the state does not belong to them. Bulgaria is yours!"

Atanas Atanasov of Democratic Bulgaria called for Dotsova to resign. On Facebook he wrote of an "unacceptable assault and bodily harm to a journalist before her eyes" and a "complete lack of any human reaction on her part". In his view, "such callousness and inhumane conduct is incompatible with the post of parliament speaker".