Thames Water has explained the cause of traffic chaos on the B480 up to Oxford city centre this morning.

It turns out that emergency works are being carried out to repair a fire hydrant.

This comes as temporary traffic signals were put in place due to water main work on B480 Cowley Road both ways at Marsh Road which caused severe delays.

READ MORE: Oxford: Cowley roadworks being carried out by Thames Water

A Thames Water spokeswoman said: "We are sorry for any disruption to motorists on the B480 while our engineers repair a fire hydrant.

"We expect to complete the necessary work in the next 48 hours during which time temporary traffic lights will be in place.”

The Oxford Bus Company also reported severe delays on its city5/5A/11/100 services.