Dozens of train managers on Eurostar services under the English Channel have walked off the job in a dispute over working conditions. The company says the strike is having only a minor effect on its schedule.

Members of the Rail, Maritime and Transport Union plan seven days of strikes over two weekends. A four-day strike started Friday, and a second three-day walkout is due over a holiday weekend starting Aug. 27.

The union says the strike is over "the work/life balance of safety-critical train managers."

Another union, the TSSA, plans to strike Aug 14-15 and 28-29.

Eurostar says it is canceling eight trains between London and Brussels and London and Paris over the four days starting Friday. It says "all passengers booked to travel this weekend will be able to."