A significant gathering formed outside a medical facility where a man accused of killing a five-year-old girl was receiving treatment.

Authorities have identified the 47-year-old suspect as Jefferson Lewis. He was taken into custody after the body of a child, believed to be Kumanjayi Little Baby, was found following an extensive five-day search operation.

The situation escalated late at night when the mourning crowd demanded that the suspect be surrendered to face justice according to their cultural customs.

In response, police deployed tear gas to disperse the demonstrators.

To alleviate the rising tensions in Alice Springs, Lewis has been transferred to Darwin.

Amid the chaos, police claim that a woman ignited a blaze under a Southern Traffic Operations vehicle using a lighter and dried grass.

Officers said a woman was arrested at the scene and the fire was extinguished before it could spread further.

Police allege the vehicle suffered about $20,000 damage.

The woman has been charged with one count of attempt arson and one count of taking part in a riot.

She remains in custody and is expected to face court next week.

For 24/7 crisis support run by Aboriginal and Torres Strait Islander people, contact 13YARN (13 92 76).