While investigations were at a preliminary stage, there was no immediate indication that alcohol or drugs played a role in the collisions, according to local law enforcement agencies.
In the first incident, Bryson was driving alone in a Lexus in San Gabriel when he allegedly struck the rear end of a vehicle occupied by three males that had been stopped for a passing train.
Bryson spoke with the occupants and then hit their car again as he departed, officials said. The trio followed him while calling police.
"The preliminary investigation indicates the collision was caused by suspect John Bryson, who is the United States Secretary of Commerce," said the police statement.
Bryson then allegedly caused a second collision minutes later in the nearby city of Rosemead, striking a car occupied by a man and a woman, the police agencies said.
Two people in the first collision were treated by paramedics after complaining of pain, the officials said. The couple involved in the second crash also complained of pain but declined medical aid.
Damage to the vehicles was minor.
Bryson, the former chairman and CEO of public utility company Edison International, was appointed 37th Secretary of Commerce in 2011, according to his official biography,
Intellpuke: This article is a compilation of reporting by msnbc.com correspondents and various news agencies; you can read it in context here: usnews.msnbc.msn.com/_news/2012/06/11/12161367-us-commerce-secretary-in-car-crashes-suffered-a-seizure?lite