A pair of manholes exploded near the corner of West 35th Street and Eighth Avenue on Wednesday morning, snarling an already busy midtown commute, authorities said.

It was not immediately clear why the two manholes -- one owned by Con Ed and the other by Verizon – caught fire, said Con Ed Spokesman Philip O’Brien. There were no injuries and the incident was wrapped up by about noon, clearing the way for the evening rush hour.

While the exact cause of the explosion was under investigation, O’Brien said it was possible that the spark was caused by left over salt from the winter mixing with Wednesday morning’s rain. O’Brien said often in situations like this the wires are taken to Con Ed’s morgue for wires in the Bronx to be analyzed.

The blasts, about one minute apart, could be heard from several blocks away. Police blocked Eighth Avenue and told pedestrians – many of whom were covering their mouths from the smell of burnt metal filled the air – to stay back.

Cable and internet outages remained hours after the blast was under control. Time Warner Cable was on the site ready to work, but had not been granted access to the site Wednesday afternoon, Spokesman Rich Ruggiero said.

It was not immediately clear how many customers had been affected.