Unintended acceleration in Toyota vehicles may have been involved in the deaths of 89 people over the past decade, upgrading the number of deaths possibly linked to the massive recalls, the government said Tuesday.

The National Highway Traffic Safety Administration said that from 2000 to mid-May, it had received more than 6,200 complaints involving sudden acceleration in Toyota vehicles. The reports include 89 deaths and 57 injuries over the same period. Previously, 52 deaths had been suspected of being connected to the problem.

Toyota Motor Corp. has recalled more than 8 million vehicles worldwide since last fall because of problems with gas pedals, floor mats and brakes. The Japanese automaker paid a record $16.4 million fine for its slow response to an accelerator pedal recall and is facing hundreds of state and federal lawsuits.

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Toyota said in a statement that it "sympathizes with the individuals and families involved in any accident involving our vehicles. We are making an all-out effort to ensure our vehicles are safe and we remain committed to investigating reported incidents of unintended acceleration in our vehicles quickly."

The automaker said "many complaints in the NHTSA database, for any manufacturer, lack sufficient detail that could help identify the cause of an accident. We will continue to work in close partnership with law enforcement agencies and federal regulators with jurisdiction over accident scenes whenever requested."

In the aftermath of the recalls, Congress is considering upgrading auto safety laws to stiffen potential penalties against automakers, give the government more powers to demand a recall and push car companies to meet new safety standards.

Toyota's U.S. sales chief, Jim Lentz, told Congress last week that dealers have fixed nearly 3.5 million vehicles under the recall and the company and its dealers have conducted 2,000 inspections of vehicles. Lentz said there was no evidence that electronics are to blame for the sudden acceleration reports.

NHTSA administrator David Strickland told lawmakers the agency had spoken to nearly 100 vehicle owners who said they had unintended acceleration following a recall fix but NHTSA had not seen pedal entrapment or sticky accelerators in any vehicles that have been properly repaired.

The government is investigating acceleration problems in Toyotas and a separate 15-month study by the National Academy of Sciences is scheduled to begin in July.