Security increases across Europe in wake of terror attacks
Soldiers and paramilitary troops toting semi-automatic rifles patrolled outside the Colosseum and inside St Peter's Square, as Italy joined the rest of Europe in beefing up security after terrorist attacks killed 129 people in Paris.
Europe has been mostly free of land-based border checks for decades, but the attacks prompted authorities in countries from Belgium to Hungary to re-impose spot inspections of vehicles.
In southern Germany, Bavarian finance minister Markus Soeder insisted the country needs to know who is entering, and criticised European borderless travel, citing the Paris attacks and the continent's migration crisis.
"The days of unchecked immigration and illegal entry can't continue," he told the Welt am Sonntag weekly newspaper. "Paris changes everything."
And if Germany cannot secure its borders, he said, "then Bavaria can take on this task".
Mr Soeder is a member of the conservative sister party of chancellor Angela Merkel's Christian Democratic Union.
He spoke as Bavarian officials confirmed that firearms, explosives and hand grenades were found when undercover police stopped a man near the German-Austrian border on November 5.
The authorities declined to confirm reports the man appeared to be en route to Paris, but said there were "reasonable grounds" to assume that there may be a link to the attacks in the French capital.
Following a request from France, Germany ramped up border controls, focusing on road, rail and air traffic from France to Germany, German interior minister Thomas de Maiziere said.
London was among cities that put in place high-visibility patrols at key locations to reassure citizens, with Metropolitan Police Commissioner Sir Bernard Hogan-Howe stressing that the "scale of the attacks and the range of weaponry used by the terrorists are a serious cause for concern".
Britain and Spain did not raise their terror threat levels, but Italy hiked its own to the second highest possible, allowing for rapid deployment of special forces if necessary.
In Rome, tourists visiting historic sites ended up seeing heavily armed troops including 700 soldiers sent to beef up security.
Italy's Sky TG24 television said police checked sewer manholes on a road leading to the Vatican to ensure no explosives had been planted.
Nordic nations like Denmark sent officers with semi-automatic weapons to patrol outside foreign embassies where usually no police are posted.
The French Football Federation said France's friendly match against England in London on Tuesday will still take place despite major safety concerns.
France beat Germany 2-0 on Friday at Stade de France in a game overshadowed by the attacks. Two explosions went off outside the stadium.
Finnish police said they were increasing surveillance in airports and harbours, while Romania announced that French institutions in the country had cancelled cultural events and a French cinema closed until December 18.
Hungary's ruling Fidesz party postponed a congress today to elect new leadership, and prime minister Viktor Orban said police would carry extra firepower while stepping up patrols at airports and the country's nuclear power plant.
Dutch prime minister Mark Rutte told reporters in The Hague that his administration will take "visible and invisible" measures to increase security, including stiffer border controls.
"Violence and extremism will never triumph over freedom and humanity," he pledged.
France's interior minister has authorised local authorities to impose curfews if needed. Bernard Cazeneuve said in a televised address that authorities are also banning all public demonstrations until Thursday.
In Poland Konrad Szymanski, prospective minister for European affairs, said that in light of the attacks, Poland cannot go ahead with EU decisions on immigration and accept refugees without guarantees of security.
He told reporters that "this is a key condition that today was put under a giant question mark in all of Europe".
Mr Szymanski is in Poland's new conservative government that is to be sworn in on Monday. The outgoing government agreed to accept 7,000 refugees from Syria and Eritrea over the next two years.
He said Poland must have "full control" of its borders and migration policy.
US officials briefed by the Justice Department after the attacks have told the Associated Press there is no evidence of any specific or credible threat targeting the American homeland.
Nonetheless, patrols are being increased and security measures are being stepped up nationwide in light of the Paris incidents.
Heavily-armed officers stood guard in Times Square and extra security was sent to French government sites in New York, Boston and Washington.
One of the officials said intelligence agents detected increased chatter encouraging an attack on the US but nothing of any credible substance.