Nigeria, Jan. 28 -- Experts have warned that the spread of coronavirus is accelerating as the death toll from the outbreak has now topped 100, with more than 4,500 cases in mainland China, CNN reports.

Amidst the growing fear on the spread of the disease to other parts of the world, China has accelerated a lockdown of many cities in the country.

The disease which was first discovered in Wuhan city in China in December has been exported to 11 other countries.

Cases have also been confirmed in every province and territory, except Tibet which has announced an indefinite closure of all tourist attractions and mandatory two-week quarantine for all travellers entering the region.

The numbers of suspected and confirmed cases have been on a d...