A former employee of a Greek shipping company shot dead three people including its owner before killing himself on Monday in a coastal suburb of Athens, police said.

The shooter, 70, broke into the company’s building in Glyfada and killed two men and a woman on the first floor before barricading himself inside.

“We heard gunshots and I hid under my desk before police officers helped us out of the building,” another employee of the company, whose identity was not revealed, told radio station Skai.

As well as shooting the owner, the gunman killed the owner’s son-in-law, who is a co-director of the company European Product Carriers.

Police were alerted at 10:11 am local time (0811 GMT) by an employee inside the building. The gunman was found dead in the basement with his weapon next to him, having “likely shot himself in the head”, said police spokesperson Konstantina Dimoglidou.

Dimoglidou added that the gunman worked for the owner’s family but did not provide further details.

In a video posted by News247, a company employee claimed the assailant was “of Egyptian origin” and “was targeting the company’s executives for revenge”.

He “ordered us to leave so the employees would not be harmed”, she added. Police earlier said officers entered the building and evacuated two women the shooter had locked in the toilets.

Nearby roads were closed and a large police presence surrounded the building.

European Product Carriers was founded in 1979 and boasts an average fleet of 35 vessels including oil tankers, according to its website.