Firecrackers and exploding light bulbs and heaters triggered scenes of panic in Paris on Sunday, as rumors of fresh shootings sent people diving for cover and calling for police.

"We were just singing along with a group of young people when everyone started to run, so we ran too," said a 23-year-old who gave her name only as Laurine.

European capitals reinforced security checks and governments held emergency cabinet meetings on Saturday a day after a series of coordinated attacks in Paris in which at least 128 people were killed.

Security measures were stepped up outside French official buildings in various capitals including Vienna, where a international meeting on the conflict in Syria was taking place.

Legendary for its beauty and bustling streets, Paris was in shock and mourning on Saturday after 128 people were killed in the worst terrorist attack in France's history.

The day after the bloodbath, the city's major attractions were shuttered from Disneyland in the east and the Eiffel Tower in the center to the Chateau of Versailles in the west, and its picturesque squares and avenues were eerily quiet.

Syrian President Bashar Assad said Saturday that French policy had contributed to the "spread of terrorism" that culminated in attacks claimed by the Islamic State group which killed 128 people in Paris.

In a meeting with a delegation of French lawmakers in Damascus, Assad said France's "mistaken policies... had contributed to the spread of terrorism."

Islamic State jihadists on Saturday claimed a series of coordinated attacks by suicide bombers and gunmen in Paris that killed at least 128 people at a concert hall, restaurants and the national sports stadium.

French President Francois Hollande also blamed the Islamic extremist group and called the coordinated assault on Friday night at six different sites an "act of war".

Bavaria's state premier Horst Seehofer said Saturday that there was "reason to believe" that a man arrested last week with several weapons in southern Germany was linked to attackers who killed more than 128 people in Paris.

"There is reason to believe that this is possibly linked" to the attacks, Seehofer told a party conference.

The Paris attacks show it is more vital than ever to coordinate global efforts to fight terrorism, France's foreign minister said Saturday, vowing that French "international action" will not stop.

"It is more necessary than ever in the current circumstances to coordinate the international fight against terrorism," Laurent Fabius said in Vienna at talks on ending the Syrian civil war.

The "heinous" Paris attacks are a violation of all religions and underline the need to intensify efforts against "terrorism," Saudi Arabia's foreign minister said Saturday as he arrived for talks on ending Syria's civil war.

"I wanted to express our condolences to the government and people of France for the heinous terrorist attacks that took place yesterday which are in violation and contravention of all ethics, morals and religions," Adel al-Jubeir told reporters in Vienna.

Berlin police on Saturday boosted security in the German capital, with barricades put up at French sites including the embassy, after the attacks in Paris that left at least 128 people dead.

"We have adjusted our protection measures overnight," a police spokeswoman told AFP, although she would not give details.

German Chancellor Angela Merkel said Saturday she will meet with ministers over the series of attacks in Paris, as she pledged to "do everything" to help France in its fight against terrorists.

"We will do everything to help in the hunt for the perpetrators and instigators, and to carry out the fight together against these terrorists," she said, adding that she will meet with ministers to discuss "the situation in France and all related questions".