China strongly condemned a deadly terrorist attack on the offices of a French newspaper in Paris, a Chinese spokesman said on Wednesday.

"We are deeply shocked at the terrorist attack and strongly condemn it," Foreign Ministry spokesman Hong Lei said, "We mourn for the victims and express sympathy to the bereaved families and the injured."

The Chinese side firmly opposes all forms of terrorism and supports the efforts made by the French side to safeguard domestic security, Hong added.

Three masked and heavily armed men stormed the offices of the satirical newspaper Charlie Hebdo in downtown Paris, earlier in the day, killing at least 12 people, including two policemen, and injuring 11 others with four in critical condition.