TREBES, France (AP) - A French bishop has paid tribute to a heroic police officer who lost his life after swapping himself with a supermarket employee in a hostage situation, saying his sacrifice helped save the nation.

Survivors and families of the victims of Friday's Islamic extremist attack packed the Saint-Etienne-de-Trebes church for Sunday's special Mass honoring Lt. Col. Arnaud Beltrame and the three others killed in the attack.

Members of the region's Muslim community were among those mourning at the special Palm Sunday service. The manager of the supermarket sat in the front row, alongside her husband, the town mayor.

The bishop of Carcassonne and Narbonne, Alain Planet, hailed Beltrame's "extraordinary devotion," saying "the whole of France has been touched by this."

Residents have been laying flowers in front of the Trebes supermarket where the attacker seized hostages Friday.

The director of the national gendarme service is meeting Sunday in Carcassonne with Beltrame's widow and French President Emmanuel Macron has also ordered a national memorial for Beltrame.

Attacker Radouane Lakdim was killed by police after Beltrame helped them storm the market.

Two people remain in custody in the investigation.

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