The Union Territory of Puducherry registered a spike in number of new Covid-19 cases with 10 infections on Thursday, according to a senior health official. The new cases were reported during the last 24 hours as against five cases registered on Wednesday, Director of Health G Sriramulu said in a release. He said that while Puducherry region accounted for nine cases, Karaikal had a solitary case of viral infection. Mahe and Yanam regions reported nil case, he said.