If one stops during the Tawaf (should he start from the beginning?)

‘Ata’ said, “If a person is performing the Tawaf and the call for the Salat (prayer) is made and the Salat starts or he is pushed from his place; after finishing the Salat he should return and start from where he had stopped.” The same is narrated by Ibn ‘Umar and ‘Abdur-Rahman bin Abu Bakr رضي الله عنهما.