Users of popular messaging app Telegram were unable to communicate with their favourite stickers and emoji for almost two hours yesterday due to a power outage at its data centre in Singapore.

"The cause of the connection issues in Asia is a major power outage in our data centre in Singapore," the company said on Twitter yesterday afternoon. It had earlier informed users that its main network switch in Singapore had gone down.

Affected users in Singapore, Australia, Malaysia, Hong Kong, Indonesia, the Philippines and Vietnam were unable to connect to the messaging app on their smartphones and computers.

Partial services were restored about two hours after the app went down, with mobile users being able to connect to the app at about 5.15pm. However, users were still unable to connect to the service's Web or desktop client, which allows them to chat on a computer, until almost an hour later.

Telegram did not respond to queries about the cause of its power outage.

"It was a slight inconvenience because we couldn't express ourselves with our favourite stickers," said writer Charlene Koh, 26, who chats with her friends on Telegram.

Reports from users saying the service was down spiked on outage.report - a website where users can report when websites or apps go offline - at about 3.30pm yesterday. More than 1,000 reports were made within the span of two hours.

Another similar website, downdetector.com, racked up almost 3,000 comments about users facing issues with Telegram.

The Telegram app is popular for its use of stickers, which users can create and customise, and its ability to support large chat groups with more than 20,000 users.

This is the second outage the Germany-based messaging service faced in about a week. On Wednesday last week, it went down in parts of Europe, with Germany hit the hardest.