The bodies of two people have been recovered from a red pickup truck, which was under water where the Baltimore bridge collapsed.
Eight construction workers were on the bridge when a ship struck it, plunging them into the waters below.
Two of the workers were rescued on the day, but the search continues for the other four – all presumed dead.
Salvage crews are working to address hazardous materials and accident investigators are on the scene.
Four of the six victims of the bridge collapse have been named so far.
At a press conference on Wednesday, Maryland State Police identified Alejandro Hernandez Fuentes, 35, and Dorlian Ronial Castillo Cabrera, 26, as the two workers recovered by divers from inside the truck. Mr Fuentes is originally from Mexico and Mr Cabrera is from Guatemala.
But divers are no longer able to safely navigate the waters because of concrete and debris found in the river, police said. They are now using sonar scans and believe that vehicles that may contain other bodies are “encased in superstructure and concrete” that came down from the bridge, an official said.
Two other missing victims, who are presumed dead, have also been named: Miguel Luna, originally from El Salvador, and Maynor Suazo Sandoval, a Honduran citizen.
Mexico’s Ministry of Foreign Affairs said earlier that two of its citizens were presumed dead – one of whom is now identified as Mr Fuentes – while another was rescued from the water.
