Personal details, including names, locations, emails, phone numbers and addresses of around 170,000 Vianet customers have been breached and leaked onto the internet.

The breach was first announced by anonymous hackers via Twitter on Tuesday, alleging that the user details of around 170,000 customers of Vianet, one of Nepal’s leading Internet Service Providers, had been compromised.

Officials at Vianet confirmed the breach.

“There has been a breach in user data,” Binay Bohra, managing director of Vianet, told the Post. “We don’t know the exact number of customers whose data has been breached, but it could be between 100,000 and 170,000.”

Issuing an official statement on Wednesday evening, the Internet Service Provider admitted that an unauthorised party had accessed personal data of users’, particularly name, location, email address and phone number.

"We have identified and fixed the source of the breach," reads the statement. "Our technical team has taken appropriate and immediate actions to reinforce existing security measures and are monitoring our system for any further possible vulnerabilities."

The incident is being thoroughly investigated by the internal team, Cybersecurity experts and the Cyber Crime Bureau of Nepal Police, reads the statement signed by Bohra. The internet service provider apologised to its customers and requested them to follow some safety measures while communicating with Vianet.

The Vianet data breach comes just a month after similar personal details belonging to users of the food delivery platform Foodmandu were leaked. In March, an individual going by the username Mr Mugger had accessed and dumped the details of over 50,000 users.

Nepalis are currently in a heightened state of concern about digital data privacy, in the wake of a scandal involving Asgar Ali, the prime minister’s IT consultant. Ali, one of the founders of the digital wallet eSewa, was allegedly involved in surreptitiously taking down a news report that was critical of him. Nepalis on social media have raised concerns about the safety of their eSewa data in light of the allegations.

[This report has been updated.]