Rome, Dec 18 (IANS/AKI): Nations will not be able to stop the "insidious" spread of terrorism and cross-border crime and keep citizens safe unless human rights are upheld, Italy's head of state Sergio Mattarella told diplomats in Rome.

"We cannot fight the insidious spread of transnational crime and terrorism without a robust network in place that unites all countries in all continents," Mattarella said.

Mattarella was addressing the diplomatic corps during a traditional exchange of Christmas greetings.

"This grave danger continues to be apparent, right up to the killing in Strasbourg of five people, including a young Italian compatriot, Antonio Megalizzi," he said.

Mattarella was referring to the gun attack on a Christmas market in Strasbourg, eastern France, on 11 December by a North-African descended suspect, Cherif Chekatt, 29, whom police shot dead in the city two days later.

"We cannot guarantee security to populations unless we respect human rights: we need more fairness and freedom in order to make the world a safer place," Mattarella added.