China’s National Health Commission on Sunday warned that a recent outbreak of the Delta variant of the coronavirus was likely to spread further in the country, Reuters reported.

China has reported more than 100 cases of Covid-19 across 11 provinces in the last week.

Mi Feng, a spokesperson of the National Health Commission, told reporters on Sunday that “seasonal factors” could lead to spread of the outbreak in other parts of the country.

Mi said that most of the infected people have cross-region travel histories, Bloomberg reported. The official also asked regions affected by the outbreak to adopt an “emergency mode”.

Wu Liangyou, the deputy director of the National Health Commission said that genome sequencing of the virus among recently infected people has showed a strain different from the source of an earlier outbreak. Wu said this suggested that the cases had originated from a new source from abroad.

Authorities have barred travel agencies from arranging cross-provincial tours involving regions where there is a higher risk of transmission of the virus. Some travel services to places of tourist attraction have also been suspended, according to Reuters.

Some cities in the Gansu and Inner Mongolia provinces have stopped bus and taxi services.

The newly-imposed restrictions are being seen as the Chinese authorities’ attempt at stamping out the virus in the lead up to the Winter Olympics, scheduled to be held between February 4 and February 20 in Beijing.

Authorities in Beijing said on Sunday that they would increase scrutiny of people arriving in the city, the Global Times reported. They have also decided to suspend a number of conferences, fora and marathon events scheduled later this month.

On Sunday, Chinese health authorities also said that 75.6% of the country’s population had been fully vaccinated as of October 23, Reuters reported. The country is now giving booster shots to adults whose last vaccine dose was at least six months earlier, and priority groups such as essential workers, elderly people and those with weaker immune systems.