French police have launched an appeal for two people they believe were involved in the shooting of a female officer on Thursday.

They have linked this incident with the brothers suspected of the Charlie Hebdo attack.

Police had not previously linked the murders of 12 people in Paris on Wednesday morning to Thursday's shooting in Montrouge, just south of the capital.

But they are now saying initial investigations have revealed a "connection" between the suspects.

The two people police are looking for are also believed to be those holding hostages in a supermarket in the French capital.

The poster circulated by French authorities | Image via @prefpolice on Twitter

The shooting of the officer happened after police and maintenance workers were called to the scene of a traffic accident involving a grey Renault Clio.

Police say the gunman was wearing a bullet-proof vest and was carrying a pistol and an automatic rifle.

He opened fire and killed the trainee policewoman, named as Clarissa Jean-Philippe (25). A street sweeper was seriously injured.

Witness Ahmed Sassi (38), who was watching from his kitchen window, said "panic" broke out.

He said he saw "a police officer standing in the road. A man with dark clothes shot them at point blank range, while continuing to run."

The shooting is being treated as a "terrorist act" by the French authorities.

Security forces detained a man soon afterwards, although police said he was not the shooter. They then raided a nearby hotel but the operation was unsuccessful.

The attack came just hours before a minute's silence was held across France in honour of the Charlie Hebdo victims.

Police are hunting two men in connection with the magazine atrocity, brothers Said and Cherif Kouachi.