At least five people were killed and another three were reported missing in a fire on a tanker moored near Athens, the Merchant Marine Ministry said on Friday.
The Panamanian-flagged, Greek-owned tanker Friendshipgas was undergoing repairs at Perama docks near the capital and the fire that broke out on Thursday is believed to have started from a welding accident, the ministry said.
"There was an explosion during maintenance work using open flames," a press officer said. "The bodies of five men were retrieved from one of the tanks and other areas, including the ship's Filipino first mate," she told AFP.
Another three people are feared to be missing based on statements from the local metalworks union, families and colleagues, the ministry said.
Four members of the maintenance crew were hospitalised earlier in the evening with burns and fractures.
Firefighters battled for over four hours on Thursday to keep the fire from spreading to a neighbouring vessel and subsequently to extinguish it altogether.
"Fires on tankers are very difficult to contain because they reach very high temperatures," fire department spokesman Yiannis Kapakis told state TV Net.
Unions have often protested poor safety conditions at Perama.
"Shipping rates are up and shipowners are always exerting pressure for repairs to be carried out as quickly as possible," metalworkers union representative Sotiris Polikoyiannis told private Flash Radio.
Two maintenance crew representatives were arrested over the incident.
The union on Friday began a three-day strike in response to the accident.
Four people were killed in an accident in Perama a decade ago and another two died last year, media reports noted.