US and UK officials have confirmed that updated guidance will be issued because of the current terror threat.

A UK official said the travel advisory will not be country-specific and it will also not go as far as advising against travel to Europe.

The advisory will be issued in response to intelligence on an al-Qaeda plan to assemble teams of gunmen and send them into crowded places to kill western civilians, similar to the 2008 attacks in Mumbai.

Al-Qaeda planned to carry out co-ordinated attacks in cities in the UK, France and Germany, intelligence sources said.

After intelligence details of the plot had been leaked to the US media last week, officials said that the plan has not been stopped but that an attack is not expected to be carried out imminently.

Officials said no arrests had yet been made, and that several individuals were still under surveillance.

The suspects include British citizens of Pakistani and German citizens of Afghan origin.

US officials said that the travel alert will be issued on October 3.