PHILADELPHIA — Striking transit workers were preventing some regional train crews from reporting to work Tuesday, causing the cancellation of a significant number of trains to the suburbs at the start of the evening rush, the city’s main transit agency said.

The Southeastern Pennsylvania Transportation Authority said it was in court seeking an injunction to prevent pickets from blocking access to facilities where its regional rail crews report to work.

Earlier Tuesday, stranded commuters jumped on bikes, grabbed cabs and hitched rides with friends or family after SEPTA and a union representing about 4,700 workers failed to reach a contract agreement.

The walkout, which began at 12:01 a.m., shut down buses, trolleys and subways that provide about 900,000 rides a day. No new talks were scheduled.