OmniRide buses in Northern Virginia are running on a reduced schedule Thursday during a strike by drivers against a contractor.

The OmniRide system said in a statement Thursday that Express buses are operating on the Emergency Service Plan, which means they are only running between Metro stations and its buses are free Thursday. Other buses are providing limited service.

The OmniRide program said passengers “should expect delays” and that the drivers are in a dispute with contractor First Transit over “issues including vacation time and bonus payments.”

It added that First Transit’s contract with OmniRide expires Oct. 31. Keolis Transit Services will take over operations on Nov. 1.

OmniRide said that is not involved itself in the dispute, but it has “encouraged” First Transit “to address the operators’ concerns and make additional resources available to them.”

A First Transit spokesperson told WTOP, “First Transit is working within the confines of the collective bargaining agreement in regard to vacation and holiday pay. Our priority continues to be providing safe transportation until the end of our contract.”

OmniRide is operated by the Potomac and Rappahannock Transportation Commission.

WTOP’s Matt Small contributed to this report.