President Mahamadou Issoufou said that five people died after demonstrations in the capital city of Niamey on Saturday. The victims were inside churches and bars that were set ablaze, he said.

The deaths came after at least five people were killed in the town of Zinder on Friday after prayer services there.

The violence erupted after the French satirical weekly Charlie Hebdo published a new cartoon depicting the Prophet Muhammad (PBUH). The issue, published on Wednesday, was the first following a January 7 attack on its headquarters that left 12 dead.

Police fired tear gas at crowds of stone-throwing youths who set fire to at least six churches and looted shops in Niamey on Saturday after authorities banned a meeting called by local Islamic leaders. A police station was attacked and at least two police cars burned.

Police sources told Reuters that two charred bodies were found inside a burned church on the outskirts of Niamey, while the body of a woman was found in a bar. She was believed to have been suffocated by tear gas and smoke, they said.

Anger mounted in several Muslim countries over the satirical newspaper's caricatures of the Prophet Mohammed (PBUH), with a second day of rioting erupting in Niger, a predominantly Muslim former French colony.

Some 15,000 people also rallied in Russia's Muslim North Caucasus region of Ingushetia against Charlie Hebdo.

French soldiers patrol at the SNCF railway station La Part-Dieu in Lyon on January 16, 2015 , after France announced an unprecedented deployment of thousands of troops and police to bolster security at "sensitive" sites following last week's terrorist attacks in Paris. AFP

There were also protests in Pakistan on Friday, and in Gaza the French cultural centre was defaced with graffiti, reading: "You will go to hell, French journalists".

But as security measure in Europe intensifies, the deployment of troops in Belgium came after security forces this week smashed a suspected "terrorist" cell planning to kill police officers.

Greek anti-terror police arrested at least four people suspected of links to the dismantled terrorist cell.

Among them was believed to be Abdelhamid Abaaoud, the 27-year-old alleged mastermind of the cell who according to media reports may have been planning the foiled attacks from Greece.

As authorities try to close in on “jihadist cells” around the world, Yemen detained two Frenchmen for questioning over suspected links to Al-Qaeda.

In France, investigators were focusing on 12 people detained early Friday and questioned over "possible logistical support" they may have given to the Paris gunmen -- terrorist brothers Said and Cherif Kouachi and Amedy Coulibaly, sources said.

In London, authorities were mulling "further measures" to protect police "given some of the deliberate targeting of the police we have seen in a number of countries across Europe and the world."