LOS ANGELES - Director Kevin Smith has sparked a debate about airline policies toward obese passengers after he says he was kicked off a Southwest Airlines flight from Oakland, Calif., to Burbank, Calif., on Saturday for being too heavy.

The "Clerks" director sent out a series of Twitter messages detailing the events and expressing outrage that he was told by airline employees to leave the plane even though he insisted that he fit in his seat.

"I know I'm fat, but was [the airline] really justified in throwing me off a flight for which I was already seated?" he wrote. "I broke no regulation, offered no 'safety risk.'"

Smith said the incident took place Saturday and that he was eventually able to make it to L.A. on another Southwest flight.

Southwest is one of many airlines that require overweight customers to purchase two seats if they cannot comfortably fit into one seat. The airline determines this in part based on a passenger's ability to lower both armrests while sitting on the plane.

Smith insisted he could lower both armrests.

Southwest issued an apology to Smith on its Twitter feed. "We are sincerely sorry for your travel experience on Southwest Airlines," the airline added in a statement.

The National Association to Advance Fat Acceptance has called for a boycott of Southwest, but the airline said the weight policy has been in place for 25 years.

"The policy requires passengers that cannot fit safely and comfortably in one seat to purchase an additional seat while traveling," the airline said in a statement. "This policy is not unique to Southwest Airlines, and it is not a revenue generator. Most, if not all, carriers have similar policies, but unique to Southwest is the refunding of the second seat purchased (if the flight does not oversell), which is greater than any revenue made."

LOS ANGELES TIMES