Multiple servers of the All India Institute of Medical Sciences (AIIMS), a federal government hospital that caters to ministers, politicians and the general public, were infected on Nov. 23 with files, including patient medical records, being encrypted, a senior police official told Reuters.

"No demand of ransom has been made for restoring the servers," the police official said, speaking on condition of anonymity.

The police official added it appeared that the hack was done from outside of India but an investigation was taking place to ascertain the origin.

An AIIMS official declined to comment on the hack but said the hospital was able register some of their patients online on Tuesday after partial recovery of the servers.

Meanwhile, an official from the state-run Indian Council of Medical Research (ICMR) said on Tuesday that the institute's security systems blocked several recent hacking attempts on its servers.

The ICMR steered India's efforts to control the spread of the coronavirus pandemic and made a locally developed COVID-19 vaccine named COVAXIN with pharmaceutical company Bharat Biotech.

"We keep encountering these attacks frequently, almost once a week, but our security have been successful in blocking these attacks," said the ICMR official, speaking on condition of anonymity.

(Reporting by Shivam Patel in New Delhi, Editing by Alexandra Hudson)

By Shivam Patel