More than 5,800 people were killed and 515,000 injured in U.S. car crashes last year tied to distracted driving, according to data released on Wednesday.

The figures, culled from police reports, were released at the start of a government conference on cell phone use, texting and other distractions behind the wheel led by Transportation Secretary Ray LaHood.

The data was significant but may not show the full problem since identifying distraction as a cause of crashes, especially in fatal accidents, can be difficult, Transportation Department officials and safety experts said.

Safety officials and advocates have focused on cell phone use, texting, eating, talking to passengers and manipulating radio or vehicle controls as leading causes of distracted driving crashes.

Auto manufacturers, the wireless industry, lawmakers and other groups support state and local efforts to ban texting while driving, but outlawing cell phone use behind the wheel has less support.

Overall statistics on distracted driving are limited and the data did not break down crashes by specific cause.

Overall traffic crashes and fatalities were down last year, but the proportion of deadly accidents tied to distracted driving climbed from 11 percent in 2004 to 16 percent in 2008.

Drivers under 20 were involved in 16 percent of distracted-driver fatal crashes. Those aged 20 to 29 accounted for another 12 percent.

Some 6 percent of drivers, or 812,000 people at any one time, used hand-held cell phones while driving in 2007, while one percent used other hand-held devices to text or read.

Over 37,000 people were killed on U.S. roads last year.

(Reporting by John Crawley, editing by Alan Elsner)