Safety fencing was put up yesterday alongside Oxford's Castle Mound following further landslips on the ancient monument.

The first earth movement on the New Road side of the 11th century mound is thought to have happened on Monday night - but there were further landslips on Tuesday and yesterday. County council highways staff put up metal fencing preventing pedestrians using the New Road pavement alongside the Mound in case a landslip came over the boundary wall. The Mound was also closed to the public.

Yesterday, staff drove in wooden stakes where the landslip had taken place, to measure any further movement, and warning signs were put up. Ashley Herring, a member of the council team which put up the safety fencing, said: "The earth has slipped considerably and has moved at least a metre from where it was last night.

"The safety fencing is to make sure people don't walk on the pavement while this is being sorted out because there is quite a lot of earth moving around and the rain seems to be making it worse."

Admission to the Mound, which provides panoramic views of the city, costs £1. The fee is also included in the entry charge to Unlocked, the Castle site's heritage and information centre.

Centre operations manager Emily Hirons said staff had been surprised by the landslip, and added that the Mound had been closed to the public.

The boundary wall that separates the Mound from New Road collapsed into New Road in 1971 and was replaced by a reinforced concrete retaining wall.

Experts at the time said the wall might have collapsed under the pressure of earth and other debris building up behind it.

Greg Lowe, principal officer for repairs and maintenance at the county council, said: "We hope that it will not be necessary to have to move in with equipment to complete remedial work on the Mound.

"It will become clear in the next few days whether this will be needed. The footpath is fenced off on the adjacent part of New Road between Macclesfield House and County Hall.

"It is unlikely that there is a risk of soil slipping on to the pavement but we're not taking any chances."

The Mound, which had been closed to the public for centuries because of its proximity to the former Oxford Prison, is popular with tourists and last year, it emerged that the site was sometimes visited by amorous couples.