Rescuers are searching stormy Gulf of Mexico seas for four oil workers still missing after a drilling rig collided with an offshore platform.
Two more survivors of Tuesday's collision have been found, as well as another body, bringing the death toll in the mishap to 19, Mexico's state oil company Pemex said on Thursday.
More than 60 people have been rescued so far.
Waves knocked the Usumacinta drilling platform into a neighbouring rig late on Tuesday.
Workers on the rig, in the Kab oil field, jumped onto emergency rafts after the collision caused leaks in crude oil and natural gas pipes.
Most of the victims drowned after they abandoned the rig and their life rafts were swamped by high seas.
Television footage showed the shattered remains of one orange life boat on a Gulf coast beach, its hard fibreglass shell ripped apart.
The failure of the life boats has provoked a scandal in Mexico, and legislators called for an investigation into whether they were supplied by a company purportedly linked to the family of Marta Sahagun, wife of Vicente Fox, the former president.
Defective boats?
It was unclear whether the boats were defective or had been supplied by the company in question, Oceanografia.
But Fox, who is already the subject of a congressional probe of illegal enrichment allegations, quickly issued a statement saying "there is no link between the children of Marta Sahagun and the Oceanografia company".
Attempts on Wednesday by rescue crews in helicopters and rescue boats to reach life rafts were thwarted by six metre-high waves.
Carlos Morales, Pemex exploration and production chief, called the accident one of the worst in the company's history.
The death toll could rise as bad weather continues to hamper efforts by navy rescue teams to locate other workers.
Rough weather
Mexico's three main oil exporting ports in the crude-rich Gulf of Mexico were shut due to weather conditions - suspending oil shipments to the US.
Pemex said US consumers of its oil supplies should not suffer as it would reschedule the delayed shipments once the storm passes.
It did not evacuate any other oil platforms or shut down production as the worst of the bad weather is seen to have passed.
The company said it would take up to five days to seal the leaking natural gas and oil but that the extent of the crude spill was less than previously thought.