BENGALURU: Defence PSU Hindustan Aeronautics Limited ( HAL ), the sole manufacturer of military aircraft in India, will close all manufacturing units and other offices spread across various cities in the country, including Bengaluru, from March 24 to March 31, in wake of Covid-19 People involved in essential services — those dealing with water supply, power and security of townships, maintenance of factories and units — will function.An internal circular read: "In pursuance of the 0ffice Orders at issued by the Government of Karnataka, Maharashtra, West Bengal, UP & Telangana, it is decided that the divisions/offices at Bengaluru, Nasik, Mumbai, Barrackpore, Lucknow, Kangur, Hyderabad will remain closed from the start of the shift on March 24 to the close of the shift an March 31or till further orders. Same dispensation wilk be applicable for offices at Delhi, Vizag, Chennai and the unit at Tambram Airbase."It stated that employees working in essential services in these divisions/offices as specified will be working in shifts."Employees of other departments shall remain in the headquarters (Bengaluru). They will be available on phone and electronic means of communication at all times during the period and can be called for duty as and when required," the circular added.