#JeSuisJuif began trending shortly after it was revealed a second siege was unfolding at a Jewish supermarket in Paris.
Two people are reported to have been killed after a gunman linked to the Charlie Hebdo murders and suspected of shooting dead a policewoman, took six people, including children, hostage.
The scene in Porte de Vincennes in eastern Paris where reports have emerged of a fresh hostage situation at a Jewish supermarket
Police are at the scene Hypercasher Vincennes, a kosher store, in Porte de Vincennes in the east of the capital.
The Associated Press reports police have ordered all shops to be closed in the neighbourhood.
The Board of Deputies of British Jews on Friday issued a statement in response to the latest incident.
It said it is “closely monitoring the situation in France where a number of hostages have been taken at a kosher supermarket in Paris.
“We are in close contact with our counterparts in France, the Conseil Représentatif des Institutions juives de France (Crif), and stand in steadfast solidarity with the French Jewish community at this difficult time.”
According to the Jewish Year Book, there are 380,000 Jewish people in Paris.
Last year, a record 3,270 French Jews emigrated to Israel — a 63% percent hike from 2012.
The Jewish Agency, which promotes emigration to Israel from the Jewish diaspora, estimates that figure could spike to 5,000.
The man at the centre of the latest siege to hit the French capital has been named as Amedy Coulibaly, 32, who officials believe is connected to the brothers behind the slaughter of 12 people at the satirical magazine on Wednesday.
Coulibaly is also said to have been responsible for the killing of a policewoman yesterday in the Parisian suburb of Montrouge.
Officials said the hostage-taker opened fire in the market before telling police who flooded the area: "You know who I am."
Police issued a photograph of Coulibaly and appealed for help tracking him down as part of the investigation into the "voluntary homicide" in Montrouge.
Police have issued photos of Hayat Boumeddienne (left) and Amedy Coulibaly who are wanted by police in connection with reports of a shoot-out in Porte de Vincennes in eastern Paris
They are also attempting to trace Hayat Boumeddiene, a 26-year-old woman.
The latest incident means police and security forces are now locked in two separate hostage situations at the same time, with Charlie Hebdo attackers Said and Cherif Kouachi holed up in an industrial estate with a hostage in a town around 25 miles north of Paris.