It is not yet clear whether the two incidents are linked to piracy, which is common in the region, or the work of rival fishing gangs jostling for each other's waters.
The first occurred last Friday, when four vessels carrying 20 crew members from Suriname and neighboring Guyana were attacked by assailants carrying guns and cutlasses.
Five survivors have so far been rescued or found their way to shore, while three dead bodies have been recovered. The fate of a dozen is still unclear.
Then on Wednesday, attackers struck another vessel, killing its captain, according to Colonel Jerry Slijngard, in charge of the Suriname coast guard.
The whereabouts of the vessel, the number of crew it was carrying, and their fate are all unknown.
Suriname's President Desi Bourterse termed the attacks a tragedy but said fishing gang rivalry, as opposed to piracy, may have been the cause.
"We empathize with the families and as government we will do everything to find the right information," he told reporters late Thursday.
Authorities in both Suriname and its western neighbor Guyana have arrested several fishermen in connection with the attacks.
Darmandew Persaud, a survivor of last Friday's attack, said the assailants were armed with curved blades and firearms.
"They chopped and beat the fishermen with bamboo sticks before robbing them," he said, adding he had survived by drifting in the deep sea before being found by an air rescue mission.
The fifth survivor swam ashore and walked for five days along the morass to reach help.
The attacks have had a chilling effect on Suriname's fishing industry, which is worth around $45 million annually.
Mark Lall, secretary of the Fisheries Collective Association, said all fishing vessels have been recalled.
He added that dwindling fish stocks were creating frictions between fishermen, exacerbated by authorities handing out too many fishing licenses.
Authorities say they have little hope of finding more survivors.
Eyewitness? Submit your stories now via social or:
Email: eyewitness@pulse.ng
