The France Blue website reported that several customers were inside the bank and being held hostage.
Police were mobilized and armed response officers were called to the scene.
“An armed man broke into the bank around 5 pm and is holding 6 people hostage, the neighborhood is cordoned off. “
The National Police of Seine Maritime tweeted: “Police operation in progress boulevard de Strasbourg @LH_LeHavre
“Respect the security perimeter set up by @ PoliceNat76600. ”
Another Twitter used posted: “The streets adjoining Boulevard de Strasbourg are currently blocked, all access prohibited between the town hall and the sub-prefecture”.
French news site actu.fr said police were concerned if the hostage taker was also armed with explosives.
Firefighters and ambulances are on the scene.
AFP reported that the man is armed with a handgun and is holding five hostages.
Images on social media showed a large number of emergency vehicles at the scene.