NEW DELHI: The central government on Monday extended its existing guidelines for restrictions for surveillance and containment of the coronavirus till January 31. While noting the decline in active cases of Covid-19 in the country, the Home Ministry added a word of caution against the new strain that has emerged in the United Kingdom. State and Union Territories must strictly adhere to the guidelines issued on November 25, including restrictions on containment zones. Restrictions on passenger trains and international flights will remain in place