Pope Francis hailed Africa as "a continent of hope" on Friday as he toured Uganda on the second leg of a landmark trip that has seen him railing against corruption and poverty.

The 78-year-old pontiff was given a rapturous welcome as he flew in to the central town of Entebbe, heading straight to Uganda's presidential palace in a small hatchback car as waving crowds gathered along the roadside, four deep in some places.

A Frenchman detained in connection with the Paris attacks drove key suspect Salah Abdeslam across Brussels the day after the atrocities without knowing he had been involved, the man's lawyer said Friday.

Ali Oulkadi, 31, charged on Monday with helping Abdeslam and taking part in a terrorist group and terrorist killings, formally denied the charges and wanted Abdeslam arrested at all costs, his lawyer Olivier Martins said.

Armenia said Friday it had arrested members of a "criminal group" which allegedly plotted to assassinate prominent politicians and public figures in the ex-Soviet republic's capital.

"Armenia's National Security Agency has uncovered and neutralized an organized criminal group which was plotting in Yerevan brutal and cynical crimes against citizens, political and public figures, as well as state bodies," the agency's deputy chief, Mikael Hambartsumyan, told a news conference.

A Belgian judge on Friday charged a sixth suspect with terrorism offenses in connection with the Paris attacks, prosecutors said, as the country pushes on with its investigation into links to the November 13 atrocities.

"Yesterday a person has been arrested in Brussels for interrogation. The investigating judge has remanded him in custody and charged him with terrorist murders and participation in the activities of a terrorist organization," the federal prosecutor said in a statement.

Up to 16,000 children have been forced to join the fighting in South Sudan since the start of this year, the United Nations children's agency (UNICEF) said Friday. 

Despite an peace agreement in August, fighting continues to rage in the two-year civil conflict in the world's youngest nation, with children suffering an increasingly heavy toll. 

Gunmen have kidnapped five Polish sailors from a cargo ship off southern Nigeria, in the latest incident in a region known as a piracy hotspot, Poland's government said Friday.

"The attack occurred at night. A group of unknown assailants boarded the boat. Five men were kidnapped" from a 16-man crew, Poland's Foreign Minister Witold Waszczykowski told reporters in Warsaw.  

Russia's Foreign Minister Sergei Lavrov on Friday said that Ankara has crossed the line by shooting down a Russian warplane this week and warned the incident could severely undermine Turkey's interests.

"We believe that the Turkish leadership has crossed the line of what is acceptable," Lavrov said at the start of talks with Syrian counterpart Walid Muallem in Moscow.

Turkish President Recep Tayyip Erdogan said on Friday he wanted to meet Russian counterpart Vladimir Putin on the sidelines of the climate summit in Paris after the downing of a Russian warplane.

"I would like to meet him face to face on Monday," Erdogan said after days of tit-for-tat accusations over the incident that has severely damaged ties.

Over 1,000 protesters on Friday staged a demonstration outside the Istanbul premises of the opposition Cumhuriyet newspaper against the arrest of the paper's two journalists, accused of spying over a news report.

The protesters who included journalists and opposition MPs chanted slogans: "Shoulder to shoulder against fascism," and "Tayyip thief, Tayyip liar, Tayyip killer," referring to Turkish President Recep Tayyip Erdogan.

Europe risks collapsing like the Roman Empire over the refugee crisis, Dutch Prime Minister Mark Rutte has warned according to the Financial Times, as his country gears up to be the next EU president.

Hundreds of thousands of people fleeing war and poverty mainly in the Middle East and Africa have landed on European shores in recent months, straining ties between the 28 members of the European Union.