Paris is to turn off the lights on its most famous attraction, the Eiffel Tower, in solidarity with the victims of the violence in Aleppo.
Paris Mayor Anne Hidalgo tweeted that the move was "to show solidarity from the city of Paris for the city of Aleppo and its inhabitants".
The lights will be turned off at 8pm local time, city authorities tweeted.
In recent days, Syrian government forces supported by Russian military air strikes have launched a major offensive to seize back control of the city from rebel groups.
The UN has accused Syrian forces of summarily killing civilians.
A ceasefire that would have seen rebels and civilians allowed to leave the city collapsed on Wednesday.
French President Francois Hollande on Wednesday joined calls for international observers to oversee the evacuation of civilians trapped in the wrecked city.