Washington, Feb 24 : WhatsApp founder Jan Koum has reportedly apologised for the recent four-hours-long outage experienced by all its users.

Days after the high-profile acquisition of the 450 million user strong service by Facebook for an eye popping 19 billion dollars, WhatsApp was marred by a long outage.

Koum acknowledged that it was their longest and biggest outage in years and affected all their users, The Verge reports.

According to the report, the outage was due to a faulty network router, which caused a cascading failure and ended up affecting WhatsApp servers.

Although, Koum didn't elaborate on the source of the router problems, it is speculated that the downtime might not have been related to the new wave of publicity from the Facebook acquisition and the accompanying load on Whatsapp infrastructure.

Kuom further assured that the company was taking new measures with its service provider to protect against future downtime and to make sure it doesn't happen again. (ANI)