PHILADELPHIA (CBS) — Police say four people were injured in a crash that involved a SEPTA bus in Northeast Philadelphia Thursday morning.

The accident happened at about 6:45 a.m. in the northbound lanes of the Roosevelt Boulevard at Allengrove Street.

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According to investigators, the accident involved a SEPTA bus, but it was not immediately known if any other cars were involved in the crash.

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Authorities say four people were taken to local hospitals with unknown injuries.

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The crash remains under investigation.