A TOWN in the south of France has held a special church service to honour those killed in an extremist attack in a supermarket.

Four people in total were killed, including a heroic police officer who voluntarily swapped places with a female hostage.

The bishop of the nearby medieval city of Carcassonne, Alain Planet, led Sunday mass at the Saint-Etienne-de-Trebes church in the town of Trebes.

Some of the town’s 5000 residents also laid flowers in front of the local supermarket where the attacker seized hostages on Friday.

The director of the national gendarme service is meeting the widow of Lt Col Arnaud Beltrame, who was killed after taking the position of a hostage.

The supermarket attack marks the worst jihadist act of terrorism since president Emmanuel Macron took office and he ordered a national memorial for Beltrame.

Gunman Radouane Lakdim was killed when police stormed the building. The 25-year-old, who was known to the authorities as a petty criminal, had not been considered an imminent threat despite previously being placed on an extremist watch list.

Lakdim, however, had pledged himself to Daesh and reportedly demanded the release of a suspect in the Novermber 13 2015 Paris attacks.

Two people remain in custody as the investigation into Friday’s attack continues.