A woman is helped by a firefighter out of the Ycua Bolanos supermarket in Asuncion, Paraguay, after a fire there killed

at least 256 people

Sunday.

Hundreds more were injured, many with serious burns, after the blaze swept through the multilevel supermarket while it was crowded with shoppers.

Authorities had not concluded what caused the blaze, but were investigating survivor accounts the fire may have been fueled by an exploding gas canister in the food court area.