A dozen northern Italian towns were on effective lockdown on Saturday after the new virus linked to China claimed two lives in Italy and sickened an increasing number of people, who had no direct links to the origin of the virus.

The secondary contagions prompted local authorities in towns in Lombardy and Veneto to order schools, businesses and restaurants closed, and to cancel sporting events and Masses. The mayor of Milan, the business capital of Italy, shuttered public offices.