UPDATED--Activity at the Port of Baltimore started returning to normal Friday afternoon after an arbitrator's ruling put striking workers back on the job.

The walkout by members of the International Longshoremen’s Association started Wednesday, supported by other unions in a show of sympathy, causing freight shipments to stop.

An arbitrator ruled Friday afternoon the strike by the ILA violated a “no-strike” clause in a national master contract the union signed off on earlier in the year. The strike was over a local supplement to the contract, which has yet to be ratified.

Workers have also agreed to a 90-day cooling off period while talks contiue over the local contract.

The port is one of the busiest in the country and handles a high number of automobile shipments.

More details are available from the Journal of Commerce and The Baltimore Sun.