The mass testing rolled out in the Binhai New Area in China's Tianjin City finished on Monday night and a total of 2,467,411 samples tested negative, local authorities told a press briefing on Tuesday afternoon.

The testing program began last Saturday morning in wake of the emergence of new local infections.

Officials also announced at the press briefing that the COVID-19 risk level in two regions in the city will be classified as low after there were no new cases for 14 days running.

The two regions, Hangu Street and Zone A and B in the cold-chain logistics area at the Tianjin central fishing port, both in the Binhai New Area, have been designated medium-risk for COVID-19 since November 10.

According to officials, preliminary investigation showed that the source of Tianjin's recent cases, which are linked to Hailian Cold Storage, was traced to imported pig heads from North America.