Chevrolet Cobalt is one of the GM models affected by the ignition-switch recall.

Washington DC - The United States’ National Highway Traffic Safety Administrationauto says probably more than 13 people have died in accidents tied to faulty ignitions on cars made by General Motors.

GM has said it knows of 13 fatalities in more than 30 accidents that arose from the ignitions, which could shut off a car's electrical systems - including airbag deployment - while the car was being driven.

It has has recalled 2.6 million cars from model years 2003-1011 and was fined a record $35 million (R368 million) by the NHTSA earlier in May for hiding the problem for years.

GM also faces lawsuits by victims of the accidents that analysts say could eventually add up to billions of dollars.

The NHTSA said on Tuesday it had been working to link the names of the 13 victims on GM's list to their families.

“They deserve straight answers about what happened to their loved ones.”

The agency said: “The final death toll associated with this safety defect is not known to the NHTSA, but we believe it's likely that more than 13 lives were lost.”

It pointed out, however, that GM was in a better position to know how many more deaths were involved, based on its information from incident reports and lawsuits.

The independent Centre for Auto Safety said in a March letter to NHTSA that records showed 303 deaths in accidents in which the airbags did not deploy in Chevrolet Cobalts and Saturn Ions, two of the GM models recalled over the ignition problem.

But those deaths could not readily link the airbag non-deployment to the ignition problem.

The centre added that the toll would probably be higher if other models also covered by GM's ignition recall were included.

It criticised the NHTSA for not having investigated the problem earlier.

“The NHTSA could and should have initiated a defect investigation to determine why airbags were not deploying in Cobalts and Ions in increasing numbers,” it said in the March letter.