Investigators say the suspect has not yet been identified A manhunt has been launched in Paris after a gunman attacked offices of the newspaper Liberation and fired outside the HQ of the bank Societe Generale.
A photographer, 27, was critically hurt at Liberation. The gunman later forced a motorist to drive him to the Champs Elysees before allowing him to go.
Police are looking for the same man who broke into the Paris offices of the 24-hour news channel BFMTV on Friday.
Police have now been stationed outside all the main media offices in Paris.
Gunman during Friday's attack at BFMTV At a news conference, investigators held up two images, one of the suspect in a street and another picture, from BFMTV surveillance cameras, which was earlier shown on Le Parisien's website.
Paris prosecutor Francis Molins said the "most likely possibility" was that a lone gunman was behind the three attacks and the hijacking. He said the suspect had not yet been identified and the motive was still unclear.
The man is said to be between 35 and 45 years old, between 1.7m and 1.8m tall (5ft 6" and 5ft 10") and shaven-headed.
The BBC's Christian Fraser in Paris says the gunman had walked into BFMTV on Friday morning and emptied the chamber of his gun in the reception area.
"Next time, I will not miss you," the man had said to an editor he threatened.
Christian Fraser in Paris says there is a "huge manhunt" under way Our correspondent says that, for a time on Monday, a police helicopter hung over the Champs Elysees amid fears the gunman might be heading towards the Eiffel Tower, but it is speculated that he might have gone into the metro.
People have been encouraged to stay indoors.
Police say the suspect is calm and assured, our correspondent reports, and each time has walked away from the scene of his attacks.
French media say the suspect told the motorist he hijacked that he was armed with grenades.
President Francois Hollande, who is in Israel, said the priority was "to stop an individual who had tried to kill and could try to kill again".
