An explosive device was found on Tuesday under a subway-car seat in Rome and bomb-disposal experts were examining whether it was an attempted Christmas season terror attack, officials said.

The ANSA news agency said the device was in a package that had wires, pipes and explosive powder.

There have been growing concerns in Europe about holiday season attacks following a suicide bombing in Sweden and official fears of an assault on a European city modelled on the deadly shooting spree in Mumbai, India.

Rome has also been the site of violent anti-government protests in recent weeks during which demonstrators have set off flares, firecrackers and other devices; another such protest is planned for Wednesday.

The office of the Rome mayor said explosives experts were at work to ascertain what kind of device it was.

ANSA and Apcom news agencies said the device was found on Tuesday inside a train during a stop at the Rebibbia station, on the outskirts of Italian capital. The reports said the area was cleared, though the station was not closed and service not halted.

ANSA cited a press release by the Atac company that runs the subway. Nobody was immediately available at Atac.

Rome Mayor Gianni Alemanno said it was “worrying.”

“Bomb disposal experts are looking into what it is, whether it’s a dangerous device that was capable of exploding or an inactive object,” Mr. Alemanno told Apcom.

Apcom said the device had been left in a grocery bag underneath a seat, and was spotted by the conductor in the morning.

Last year, a Libyan man set off a small bomb while trying to enter an army barracks in Milan, seriously injuring himself and slightly wounding the guard who stopped him. Officials said at the time that the man appeared to be opposed to Italy’s military missions overseas- Italy has troops in Afghanistan.

European officials typically step up security around the holidays. A Nigerian man with explosives taped to his underwear tried to blow up a plane last year as it approached Detroit on Christmas Day. Umar Farouk Abdulmutallab, who had studied in London, boarded the Northwest Airlines flight to Detroit from Amsterdam.

Iraqi officials claimed last week that captured insurgents believed that the suicide bombing in Stockholm that killed only the bomber was part of a series of Christmas season attacks.

Both British and German officials have insisted there have been no new specific threats to their countries over the festive period.

Britain’s terror alert has remained unchanged at “severe” while Germany upped its terror alert on November 17, when Interior Minister Thomas de Maiziere warned of an increased threat from Islamic extremists.

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