Google has apologised for a system error that led to some web users experiencing slow delivery or complete outages of many services offered by the company.

The problem occurred yesterday (May 14th) at 07:48 local time - late in the afternoon in the UK - and lasted for about one hour.

Twitter users reported outages or very slow service for Google search and Gmail, among other applications, with the problem appearing to affect users in multiple countries.

Google said that the issue seemed to affect about 14 per cent of its users in total.

It blamed the problem on an error that saw some of its web traffic directed through Asia, causing a bottleneck or "traffic jam".

"We've been working hard to make our services ultrafast and 'always on', so it's especially embarrassing when a glitch like this one happens," said Google operations senior vice-president Urs Hoelzle on the Official Google Blog.

He added: "We're very sorry that it happened."

A chart from Arbor Networks posted by Wired.com revealed that average traffic to Google from the ten top internet service providers in North America plummeted during the outage.