Officers and firefighters are currently at the scene in Ingram Road, close to the junction with Cross Ingram Road.
One woman, whose car is parked inside the area cordoned off, said she was told that some nearby properties might also be evacuated as a precaution.
She said it appeared there had been a build-up of gas inside drains running under the street and manhole covers had been blown off.
The force of the blast is also understood to have caused damage to the road itself.
A West Yorkshire Fire Service spokeswoman said: “Some chemicals had entered the waterway though the sewers, reacted and blown the manhole off. We don’t yet know how that happened and we’re trying to ascertain what the chemical is.
“We’re working with Yorkshire Water as well."
She said eight fire engines had initially been dispatched just before noon, but only four now remained at the scene.