Possibly a stoppage, did you try to flust them?

If it is a stoppage call a plumber as no one knows more about servicing sewers and drains then the licensed folks who install them

It did flush & I did call a plumber who came the next a.m. and told me it was not sewage but sediment from the water pipe, probably from a flushing of the community drain, either planned or following a water main break somewhere locally. Problem is gone, whatever it was. Thank you for your response.

Your very welcome,NOW go check all your aerators for sediment