U.S.-based Zoom Video Communications Inc has apologized for security flaws and says it is working to fix them. Problems have included “Zoombombing”, when uninvited users gatecrash a video conference.

Taiwan and Germany have already curbed the use of Zoom, while Google banned the desktop version from corporate laptops this month.

“Zoom is a not a safe platform,” the Cyber Coordination Centre (CyCord) of India’s ministry of home affairs said in a 16-page advisory.

The government body also provided guidelines on how to avoid unauthorized users from carrying out malicious acts while using the tool.

A Zoom spokesman said the company was in talks with governments around the world and was “focused on providing the information they need to make informed decisions about their policies”.

The company founder and Chief Executive Officer Eric Yuan earlier this month apologized for what he called falling short of “the community’s – and our own – privacy and security expectations.” The company was dedicating resources to identify and fix the issues, he added.

Zoom has enjoyed a surge in usage since the virus outbreak began, as millions of people use it to stay connected while isolating themselves. In March it had about 200 million people using its system every day, up from 10 million last year.

“Before Zoom’s explosive growth, there were a few key cybersecurity precautions that were overlooked,” said Logan Kipp, director at cybersecurity firm SiteLock.

“From the get-go, there should have been stronger encryption methods in place and perhaps additional consideration about third-party data sharing,” he said.

Zoom’s mobile app saw a sharp surge in downloads in India as the country enforced a nationwide lockdown late last month to curb the spread of the coronavirus.

Even some Indian government officials have held discussions with industry executives to discuss coronavirus relief measures via Zoom. One media report this week said the Indian government was advising its ministers not to use third-party software for sensitive meetings.