More than 240 people have been killed in France in attacks since 2015 by assailants who pledged allegiance to IS or were inspired by the group.
"THE THREAT IS EVERYWHERE " France is part of a USA -led coalition fighting Islamic State in Syria and Iraq and has thousands of soldiers in West Africa fighting al Qaeda-linked militants. France is part of that coalition. "Unfortunately the threat is everywhere", Collomb told reporters in Trebes.
Collomb said elite French forces stormed the market and killed the gunman after hearing gunshots inside.
The officer was shot and stabbed before anti-terror police moved in to kill the attacker and end the siege.
Top anti-terror prosecutor Francois Molins said Lakdim had convictions for carrying a banned weapon and for drug use and had spent a month in jail in 2016.
Three people were killed in southwestern France when a gunman held up a vehicle, opened fire on police and then took hostages in a supermarket. Union leaders say planned consultations on the details are just window dressing.
French national police earlier said at least two people were killed and a dozen wounded in the incident.
Some commentators have reached into the past to draw parallels with more recent confrontations, particularly to 1995 when weeks of strikes paralysed the country and forced the government to abandon a pension reform.
Earlier on Thursday, after British Prime Minister Theresa May met with German Chancellor Angela Merkel and French President Emmanuel Macron in the margin of the European Union summit in Brussels, a spokesperson of Downing 10 claimed that "the UK, Germany and France reaffirmed that there is no plausible explanation other than that the Russian state was responsible".
Speaking in Brussels, where he is attending an European Union summit, Macron offered his "full support" to everyone involving in the situation.
"If Emmanuel Macron gives ground on such a symbolic reform and so close to his election (last May) his image of a reformer will be destroyed", veteran political commentator Alain Duhamel said last week.
Klopp would have signed Bundesliga man instead of Salah
Liverpool Football Club remain adamant today that Mohamed Salah will not be sold to Real Madrid or anyone else in the summer. Emre Can has insisted he has all the attributes to excel at a "very big club" as fears intensify around his Liverpool exit.
A hostage taker in southern France has asked for the release of Paris November 2015 attacker Salah Abdeslam, BFM TV said, citing an anonymous source.
A number of trains between Lorraine and Luxembourg, and between Paris and Luxembourg, were cancelled on Thursday.
The school system in the Trebes region says all students are safe and will remain inside schools until further notice.
Unions told The Local that while they regretted the impact of the strikes on travellers their cause justified the travel chaos. "Alas, this one struck without us being able to counter it", Mr Collomb said.
Local authorities tweeted that the area was out-of-bounds to the public. Then he fired one police officers in Carcassone, wounding an officer in the shoulder before heading to Trebes about 8 km (5 miles) to the east, where two more died in the Super-U supermarket.
The incident is continuing inside a supermarket in the small town of Trebes.
It took three hours to bring the situation under control when the police shot dead the gunman in a cross firing.
The national gendarmerie said its flags would fly at half-mast on Saturday in tribute to the slain officer, while a white rose hung on the door of his own base in Carcassonne.
BFM TV reported that he claimed allegiance to Islamic State.
Public opinion is largely behind his bid to remove some job privileges for new hires at debt-laden state railway operator SNCF and many analysts believe the reform effort is a crucial test of strength.
Three people were killed in southwestern France on Friday when a gunman held up a vehicle, opened fire on police and then took hostages in a supermarket, screaming "Allahu Akbar".