Travellers are currently occupying land near Sudbury Community Health Centre.
They were first reported to have set up camp in the car park of Delphi Diesel Systems on Sunday, but were moved on by the owners.
It is believed they dispersed into separate groups, with some travellers remaining at the site outside Sudbury Community Health Centre, which has prohibited buses from dropping off patients and passengers.
A spokesman for NHS Property Services, which owns the building, said: “We have been working with local partner agencies, including the Norfolk and Suffolk Gypsy and Traveller Liaison Service, since the weekend and will soon be initiating a legal procedure to ensure the vehicles move off the site as soon as possible.
“Patients should continue to attend appointments at the centre as normal.
“Revised vehicle access arrangements are in place so patients can still get to the centre but, unfortunately, public transport buses cannot currently access the site and are dropping off passengers nearby on Church Field Road.”
Other travellers, which had been reported in Alexandra Road, have since left the site.
A Suffolk Constabulary spokesman said: “Police are aware of two traveller encampments in Sudbury – one near to the community health centre and a smaller one on Alexandra Road.
“We are working closely with partner agencies, including the town council, under agreed protocols around unauthorised encampments.
“Welfare checks have been carried out and co-ordinated by the traveller liaison officer.
“We continue to liaise closely with the travellers and we will continue to monitor the situation.”
A Sudbury Town Council spokesman said a group of travellers were also moved from Delphi sports field, and had since relocated to Acton Lane.
Travellers were reported to have occupied land in the long-stay car park in Station Road in September.