TEMPE, Ariz. (AP) — A strike by transit bus drivers affecting tens of thousands of riders in Phoenix's eastern suburbs is in its second day, though there are indications of progress in contracts talks.

The strike began Thursday, shutting down 40 routes in Chandler, Gilbert, Mesa and Tempe, along with express routes from those cities to Scottsdale and Phoenix. The affected routes serve some 57,000 riders daily.

Negotiators for the Amalgamated Transit Union and operator First Transit plan to continue negotiations Friday.

ATU Local 1433 president Bob Bean says there's optimism an agreement will be reached.

The union says the company provided a new offer on a key issue, job security.

First Transit spokeswoman Jen Biddinger also says the sides are making progress.

Copyright 2013 The Associated Press.