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

A 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 modeled on the deadly shooting spree in Mumbai, India.