Failed fire attack in Milan metro

The fire occurred at one of the city's busiest stations

Italian police are investigating a fire which broke out in one of Milan's main metro stations on Saturday night.

Milan is though to be the European hub of al-Qaeda

The tap of a gas cylinder was set alight at around 2245 (2045 GMT), filling the station with smoke and delaying trains for about half an hour.

However transport police quickly located the fire and put it out, police officials said.

Anti-terror police took over the investigation after a threatening note written on cloth was found in a nearby rubbish bin, they said.

Previous attacks

The note had the phrase "We will fight for the cause of Allah and we will not stop until you submit and worship the one and only God, Allah," written in Italian, and the phrase "Allah is Great" in Arabic.

The Duomo metro station lies underneath Milan's huge Gothic cathedral, where two of the city's three underground lines meet.

Police are studying surveillance tapes of the scene, and are investigating if the incident is linked to a recent swoop on suspected members of Osama Bin Laden's terror al-Qaeda network.

Italy has increasingly become the focus of terror investigations with suspects thought to have established one of their main European bases there.

In February this year, nine Moroccan men were arrested following the discovery of an apparent plot to launch a chemical attack against the US embassy in Rome.

A motive has also yet to be uncovered in the case of a blast near Rome's Interior Ministry.