The Swedish Coast Guard has warned that 17 crew members on an NSC Holding bulker may have to be evacuated as a cargo fire continues to burn after six days.
The blaze broke out among timber on the foredeck of the 31,800-dwt handysize Almirante Storni (built 2012) on the afternoon of 4 December off the island of Vinga near Gothenburg.
The Coast Guard is on site with several response vessels to control and extinguish the fire, together with other emergency organisations.
The situation is described as stable, with extra extinguishing resources having an increased dampening effect on the fire.
Efforts to bring the vessel to port are continuing.
The Coast Guard said: "A slight improvement in the firefighting can be seen. The water volumes are dampening more now with the increased resources at the site, in combination with calmer weather."
NSC Holding had said on Monday that the blaze was "largely extinguished".
But Coast Guard rescue leader Fredrik Hallerstrom said in a statement: "My assessment is that since such resources are required over such a long period of time, without still being able to extinguish the fire, we are approaching the situation where a rescue must take place.
"There are many actors involved and extensive cooperation is required, on several levels. The situation remains worrying."
Seafarers questioned
Worse weather is on the way, he added.
Further investigation of remaining heat nests was planned on Friday.
NSC said: "All parties are focused on the immediate tasks in hand: securing any further fire hot spots and moving the vessel to an appropriate port facility at Gothenburg."
"The situation is pretty much under control and a scheduled plan is being followed. The vessel shall arrive inside by its own engine power and escorted by tugs," the company added.
A preliminary probe has begun, led by Swedish prosecutors.
Initial questioning of the crew by the Coast Guard has taken place on board.
The stacked timber burns easily, rendering the situation complicated, the Coast Guard said.
No injuries have been reported. The bulker's operational capacity is limited but it is still functional, the organisation added.
"The aim is to gain control of the fire and take the ship to a designated quay where the fire can be extinguished," it said.
NSC earlier told Swedish media it had been in contact with the master, but the cause of the incident was not clear.
The Almirante Storni had arrived at anchorage outside Gothenburg on 4 December, from Ljusne in eastern Sweden.
It has insurance from the North P&I Club.
