MACAO -- China's Macao Special Administrative Region (SAR) reported 31 locally transmitted COVID-19 cases on Sunday, according to the Novel Coronavirus Response and Coordination Center of Macao.

The patients included 21 females and 10 males, aged between eight months and 89 years. Eight of them had developed symptoms, while 23 others were asymptomatic, the center said.

The Macao SAR government has decided to close public venues, including schools, parks, museums and sports facilities starting on Sunday in an effort to reduce crowd gathering.

Public sectors, except those providing emergency or essential services, will suspend operation on Monday and Tuesday.

The Macao SAR government urged all residents to stay at home. All businesses, except for supermarkets and grocery stores, were asked to remain closed until further notice, and all restaurants suspended dine-in services.

The source of the infections was unclear yet, Ao Ieong U, secretary for social affairs and culture of the Macao SAR government, told a press conference.

Ho Iat Seng, chief executive of the Macao SAR, urged all public departments to do their utmost to curb the spread of the virus, and make the safety of residents their top priority.

Those leaving Macao for neighboring Zhuhai city in South China's Guangdong province are required to present negative nucleic acid test reports effective within 24 hours instead of the previous seven days.