Beijing, Oct 11 (IANS): As China imposes fresh lockdowns and travel restrictions amid Covid surge, the country has detected new Omicron sub-variants BF.7 and BA.5.1.7, which are highly infectious with greater transmissibility.

BF.7 (also known as BA.2.75.2) is a sub-lineage of the Covid Omicron variant BA.5.2.1.

According to local reports, the BF.7 was detected on October 4 in Yantai and Shaoguan city.

The subvariant BA.5.1.7 was detected in the Chinese mainland for the first time, as reported by Global Times.

The World Health Organisation (WHOO) had warned against the highly infectious BF.7 subvariant.

Meanwhile, holiday spending during China's Golden Week has plunged to its lowest level in seven years, as broad Covid curbs discouraged people from travelling or spending, while a darkening economic outlook continues to erode consumer confidence.

For local officials, doubling down on zero-Covid is a way to toe the Party line, demonstrate their loyalty to President Xi Jingping, and prevent any large-scale outbreak that could jeopardise their career weeks before the Party Congress.

New Covid cases are spiking across mainland China, prompting many local authorities to tighten controls on movement.

Three of Shanghai's downtown districts on Monday ordered entertainment venues such as internet cafes to close temporarily, according to official announcements.