A drone has hit a US-owned gas storage tanker at Egypt's Mediterranean port of Damietta, maritime security firm Ambrey said on Wednesday, citing an initial assessment of the incident.

Port services firm Inchcape said in a separate message that two gas tankers had caught fire at Damietta.

The drone hit floating storage tanker Energos Winter, causing a fire that then spread to another vessel, Gaslog Salem, three trading sources familiar with the incident said. Two separate security sources said the cause of the blast was a drone strike.

The crew was evacuated, and the fire had been brought under control, Ambrey said, adding that no party had claimed responsibility.

Egyptian authorities launched an investigation into the circumstances of the incident but have not defined the incident as an attack.

Egypt’s Petroleum Ministry disputed the reports of a drone strike, stating that the the fire broke out on a regasification vessel and a storage vessel.

The Petroleum Ministry added that no fatalities or injuries resulted from the incident and that emergency teams are on scene assessing the circumstances of the fire.

This is a developing story.