It was one of several rallies taking place on Monday as Occupy protesters marched on a number of busy US ports seeking to disrupt cargo traffic.

By trying to hamper port operations, organisers hoped to call attention to US economic inequalities, high unemployment and a financial system they complain is unfairly tilted toward the wealthy.

In Long Beach, at least one protester was taken away in handcuffs after the skirmish, and demonstrators later left the area to block traffic along a main thoroughfare through the port. But as rains grew heavier and police converged in force threatening arrests, protesters began to disperse on their own.