The agency charged with monitoring off-road racing on federal lands is promising to increase staffing and crack down on violations of racing permits.

Sens. Barbara Boxer and Dianne Feinstein of California asked the Bureau of Land Management to respond to several questions they had after an accident in August killed eight people and injured 10 in the state's Movaje Desert.

Bob Abbey, director of the BLM, told the lawmakers in a letter obtained Wednesday that the agency will increase its presence at all the events it approves on federal lands, but he did not provide further specifics. The agency had only one ranger on duty patrolling the 50-mile race course where the accident occurred.

Boxer said the agency's response makes it clear that more trained personnel need to staff the races.

Abbey said the agency continues to cooperate with the California Highway Patrol as it investigates the crash. It's also reviewing pending requests to conduct off-road races on a case-by-case basis.

BLM officials have the authority to discontinue an event if they determine that the sponsor has failed to meet permit requirements.

"The BLM will not tolerate any deviation from permit stipulations," Abbey told the lawmakers.