April’s container cargo numbers for the Port of Los Angeles fell more than 6 percent from a year ago, port officials announced Friday.

Nearly 663,000 containers moved through the port last month, down 6.1 percent from the same period last year. Port officials said cargo volumes dropped last month from a year ago because importers brought in more inventory last April to have it available in case cargo movement at the Ports of Long Beach and Los Angeles slowed once shipping lines and dock workers began contract negotiations later in the year.

Imported cargo volumes fell 9.9 percent last month to about 328,000 containers, while exports dropped 15.8 percent to about 146,000 containers.

Container cargo volumes for the first four months of the year are down 5.3 percent overall when compared to this time period last year, port officials reported. Cargo traffic slowed to a crawl in January and February because of labor slowdowns and operational problems that have since eased.

Officials with the Port of Long Beach said they would release container cargo volumes on Monday.