A signalling fault between Dullingham and Cambridge is causing rail delays this morning.
Train services between Ipswich and Cambridge are returning to normal but some services may still be delayed by up to 20 minutes or revised.
Disruption is expected to last until 11.10am.
Greater Anglia said the 10.44am service from Cambridge to Ipswich will start at Newmarket at 11.04am, while a rail replacement bus operated by Youngs will run from Cambridge to Newmarket only departing at 10:44.
For the latest travel information, see www.journeycheck.com/greateranglia/