LOS ANGELES >> Truckers in a long-running dispute with three companies at the ports of Los Angeles and Long Beach have started what they say is an indefinite strike.

The truckers argue they are full-time employees, not independent contractors, and should be paid accordingly.

Truckers’ spokeswoman Barb Maynard says workers formed picket lines Monday morning outside the companies’ yards.

The strike could have broader impacts on trade through the twin ports, the main gateway for goods going to and from Asia.

Maynard says picketers will follow trucks making runs to marine shipping terminals.

Dockworkers would then decide whether to cross those lines. Their union is negotiating a new contract with companies that ship goods through all West Coast ports.

An International Longshore and Warehouse Union spokesman says he’s unsure what dockworkers would do.