Fears of terrorist attacks in Europe have increased this holiday season following a series of incidents in various European countries, including parcel bombs that exploded in embassies in Rome.
Two people were injured when the bombs exploded at the Swiss and Chilean embassies in Rome. Italian police were checking other embassies while Rome's mayor warned of what he called a 'wave of terrorism.'
The parcel bombs were discovered just two days after police in the Italian capital found a suspicious package in a subway car. Authorities later said the device was a fake.
In Britain, police arrested a dozen people Monday in the country's largest counter-terrorism raid in two years. And the week before, Sweden escaped a suicide bombing attempt that appeared targeted at Christmas-time shoppers.
Such incidents have put Europeans on edge this holiday season and they cap a year in which many European countries have heightened their security warnings for fear of Islamist attacks.
But Britain-based security expert Bob Ayers does not believe 2010 has been a particularly dangerous year.
"What we are seeing is improved counter-intelligence, improved counter-terrorism," he said. "As a consequence, we are seeing more arrests, like what you saw in the U.K. But I do believe it is a particularly dangerous season of the year, the holiday season."
Christmas Day 2009 was marked by a botched airline bombing attempt by a Nigerian, who tried to detonate plastic explosives hidden in his underwear during a flight from Amsterdam to the United States. But even as authorities step up security in airports and elsewhere, Ayers says would-be terrorists are plotting new methods.
"The terrorists are not stupid," he added. "They look at the security processes and procedures and they figure out ways to get around them."
Europe is no stranger to terrorist attacks. Train bombings in Madrid killed 191 people in 2004. Subway bombings in London a year later killed more than 52 people. Residents of both cities were shaken, but carried on with their lives.