WhatsApp mobile application, Facebook's latest acquisition, restored its services after it was interrupted for several hours on Saturday.
The world's fast-growing web-based application experienced service outage on Saturday, prompting so many Internet users to complain on social media.
"Sorry we are currently experiencing server issues. we hope to be back up and recovered shortly" WhatsApp said on its Twitter account.
Many Facebook and Twitter users sarcastically criticised Facebook for the brief outage, with some questioning the point of the social network's move to buy WhatsApp for a hefty price.
Facebook Inc announced earlier this week that it would buy the mobile-messaging startup for $19 billion in cash and stock in a landmark deal that places the world's largest social network closer to the heart of mobile communications and may bring younger users into the fold.
The transaction involves $4 billion in cash, $12 billion in stock and $3 billion in restricted stock that vests over several years. The WhatsApp deal is worth more than Facebook raised in its own IPO and underscores the social network's determination to win the market for messaging.
Founded by a Ukrainian immigrant who dropped out of college, Jan Koum, and a Stanford alumnus, Brian Acton, WhatsApp is a Silicon Valley startup fairy tale, rocketing to 450 million users in five years and adding another million daily.