Cargo traffic at the Port of Los Angeles was up slightly last month, though the boost came entirely from an increase in the number of empty cargo containers leaving the port, according to figures released Wednesday.

Imports fell 1 percent and exports were down 7 percent compared with October 2011, but the number of empty containers sent back to Asia grew by nearly 16 percent. That gave the port a modest overall traffic increase of 0.8 percent.

The port handled 718,406 containers last month. Port officials consider anything over 700,000 a strong month.

Cargo traffic in Los Angeles has grown in most months this year, and traffic through October is up about 4.7 percent over the same period last year. The neighboring Port of Long Beach has seen its number slip in most months this year, and taken together the two ports show little if any growth in cargo moving through the region.

The Port of Long Beach is expected to released its October figures Thursday.