Intensive efforts to curb the spread of the novel coronavirus are continuing around the clock in Beijing as 15 new locally transmitted COVID-19 cases, including 12 patients and three asymptomatic carriers, were detected in the Chinese capital in the 24 hours to 4 pm on Tuesday.

"At present, the pandemic prevention and control situation in Beijing is still grim and complex, and related departments should go all out, seize every minute, to block the further spread of the novel coronavirus in the city," Pang Xinghuo, deputy director of the Beijing Municipal Center for Disease Control and Prevention, told a news conference on Tuesday.

Government departments have launched further epidemiological investigations and tracked close contacts to help prevent and control the spread of the disease, she said.

Beijing, which will host the 2022 Winter Olympic Games next month, has reported 67 locally transmitted confirmed cases, including six cases caused by the Omicron variant, since Jan 15, Pang added.

As of Tuesday, Beijing had one high-risk area, plus six medium-risk ones.

The disease has spread from Beijing to at least three provinces, the National Health Commission said on Tuesday.

At least seven people linked to cold storage operations in the capital's Fengtai district contracted COVID-19 and were identified after returning to Hebei, Shandong and Shanxi provinces for Spring Festival.

Meanwhile, China is also facing growing pressure to prevent and control the spread of the novel coronavirus from abroad, with sporadic outbreaks of COVID-19 reported in border cities in recent days.

In Northeast China's Heilongjiang province, three confirmed cases and nine asymptomatic carriers were detected in Suifenhe and one confirmed case was reported in Dongning, the cities' health commissions said on Tuesday.

Dongning and Suifenhe are port cities on the China-Russia border under the administration of Mudanjiang in Heilongjiang.

Northwest China's Xinjiang Uygur autonomous region reported six confirmed COVID-19 cases and 16 asymptomatic carriers on Monday, the regional health commission said on Tuesday.

All the cases were recorded in the border city of Horgos in the Ili Kazak autonomous prefecture.