The total of locally transmitted COVID-19 cases in Shanghai increased to 12 with three new infections reported on Saturday, the Shanghai municipal government said on Sunday morning.

Among them, 10 were in downtown Huangpu district and the rest in north Shanghai's Baoshan district.

The first case reported on Saturday was a neighbor of a confirmed case reported on Thursday in Huangpu district's Zhaotong Road residential neighborhood and had suspected contact history with the case.

Thursday was when the first three cases in this wave of infection in Shanghai were reported after nearly two months of zero local case.

The second case reported on Saturday related to mother-son connected with a case reported on Thursday. And the third new case was a colleague of a confirmed patient on Thursday. Both of the newly-reported cases live in Huangpu district.

All the 12 local cases in this wave so far are interconnected, according to the government. The first case was found when hospitals began screening their staff members with nucleic acid tests, and all the following ones were found through tracing the close contacts of the confirmed patients.

The six cases reported on Thursday were two hospital workers, two hotel workers, a resident at the same hotel, and a relative of one of them. Two cases reported on Friday were parents of a confirmed case reported on the previous day, and the third case reported on Friday, a pianist, was a friend of a confirmed case reported on Thursday and lived at a hotel in Huangpu district.

The Shanghai Municipal Health Commission said that five close contacts of the three newly-reported cases have been identified in Shanghai and placed under hotel quarantine. All the public venues, including residential communities, grocery stores, eateries, and a hotel, that they had been to over the previous two weeks have been disinfected.