Delhi Chief Minister Arvind Kejriwal today urged the centre to extend the suspension of flights to and from the United Kingdom as the country now battles the variant strain of coronavirus first detected there. "Centre has decided to lift the ban and start UK flights. In view of extremely serious COVID situation in UK, I would urge central government to extend the ban till January 31," Mr Kejriwal tweeted, raising alarm on the fast-spreading strain of the virus, 73 cases of which have been detected in India.