By Philip Pullella ROME (Reuters) - Security was heightened for the Christmas weekend in Italy and at the Vatican on Saturday after Italian police killed the man believed to be responsible for the Berlin market truck attack while other European cities kept forces on high alert.

SAN JOSE (Reuters) - Costa Rica said on Friday it was investigating whether a former Mexican state governor wanted on corruption charges had entered the country illegally.

WASHINGTON (Reuters) - The U.S. State Department on Friday warned Americans traveling to Jordan of threats from terrorist groups after several recent attacks in the country. More than a dozen people were killed, including a Canadian tourist, in two attacks by Islamist militants this week in the southern city of Karak.

MOSCOW (Reuters) - Turkish President Tayyip Erdogan gave an update on the investigation into the killing of the Russian ambassador in Ankara in a phone conversation with President Vladimir Putin on Friday which also covered the Syrian crisis, the Kremlin said. The envoy, Andrei Karlov, was shot dead on Monday by an assassin who shouted "Allahu Akbar" and "Don't forget Aleppo".

By Dustin Volz and Jason Lange WASHINGTON (Reuters) - The FBI is investigating how hackers infiltrated computers at the Federal Deposit Insurance Corporation for several years beginning in 2010 in a breach senior FDIC officials believe was sponsored by China's military, people with knowledge of the matter said.

By Emilio Parodi and Antonella Cinelli MILAN (Reuters) - Italian police shot dead the man believed responsible for this week's Berlin Christmas market truck attack, killing him after he pulled a gun on them during a routine check in the early hours of Friday.

By Lisa Barrington and Angus McDowall BEIRUT (Reuters) - Syrian rebels shelled Aleppo and air strikes resumed around the city on Friday as Syrian President Bashar al-Assad and his allies said the insurgents' withdrawal from the city could pave the way toward a political solution for the country.

By Melissa Fares and Andrew Osborn WEST PALM BEACH, Fla./MOSCOW (Reuters) - U.S. President-elect Donald Trump upped the stakes on Friday in a back-and-forth exchange with President Vladimir Putin over nuclear weapons that tested the Republican's promises to improve relations with Russia.

By Michelle Nichols UNITED NATIONS (Reuters) - The United States on Friday allowed the U.N. Security Council to adopt a resolution demanding an end to Israeli settlement building, defying heavy pressure from long-time ally Israel and President-elect Donald Trump for Washington to wield its veto.

By Chris Scicluna VALLETTA (Reuters) - Hijackers armed with what were probably replica weapons forced an airliner to land in Malta on Friday before freeing all their hostages unharmed and surrendering, having declared loyalty to Libya's late leader Muammar Gaddafi. Television pictures showed two men being led from the aircraft in handcuffs.