A helicopter owned by a firm that provides transport services for state oil company Pemex crashed into the Gulf of Mexico off the Campeche coast Wednesday morning.

The pilot and co-pilot appeared to be unaccounted for at 3:00 p.m. Mexico City time, but at least one newspaper reported that they had died.

No one else was onboard the aircraft when it came down at 6:43 a.m. approximately 11 nautical miles from Ciudad del Carmen, according to a Pemex statement.

The state oil company said that a helicopter owned by Heliservicio was involved in a “regrettable accident” near the Bay of Campeche while flying to Gulf of Mexico oil platforms.

A helicopter featured on the Heliservicio website is emblazoned with the message “at the service of Pemex.”

Pemex said that an emergency response plan was immediately activated following the accident and that two navy vessels were dispatched to search for and rescue the pilot and co-pilot. The state oil company also said that the cause of the crash was under investigation.

The newspaper El Financiero said that it was told by a source – which it didn’t name – that the pilot and co-pilot didn’t survive the accident.

Pemex has numerous drilling rigs and oil platforms in the Gulf of Mexico, including the Bay of Campeche.

With reports from El Financiero