The incident took place around 2 a.m. on Monday. It is still unclear how much damage the 183-metre vessel has sustained.
"It's something we're investigating," says Hånell.
It was probably a drone or shrapnel from a downed object that hit the ship, according to Hånell:
We still don't really know exactly what it was.
According to Dagens Nyheter, one shipyard worker was killed and two were injured in the attack.
"That's more than I know at this point," says Hånell.
Stena Bulk has around 60 tankers in service. Several of them are in the Persian Gulf after the U.S. and Israel attacked Iran on Saturday.
What do you think?