Image copyright PA Image caption Aspen officials say 50 drones will be used during the show

The US town of Aspen is swapping its annual Fourth of July fireworks display for a drone show - because of a wildfire risk in the drought-hit area.

Officials say 50 drones will light up the night sky in patriotic colours to mark Independence Day.

The 15-minute show will start at 21:15 local time (03:15 GMT Thursday).

This comes after Colorado's fire authorities introduced strict fire restrictions across huge swathes of the western state.

The Drone Light Show is being organised in the town's Wagner Park by the Aspen Chamber Resort Association (Acra).

It has invited the public to "watch the drones light up the sky choreographed to patriotic music".

"We had to come up with a highlight for our celebrations so we're doing a drone show. It should be fun, a bit new age," Acra's spokeswoman Melissa Wisenbaker was quoted as saying.

"If we are having these increased fire dangers and risks every year, then we would like to have alternatives so people can end the night on a good note," she added.

Media playback is unsupported on your device Media caption Swarm of drones form the Olympic rings at 2018 Winter Games opening ceremony

Acra may have been influenced by a spectacular drone show during the Winter Olympics 2018 ceremony in Pyeongchang.

A swarm of unmanned aerial machines then formed the five Olympic rings in mid-air.

However, the organisers later said the spectacular sight of 1,218 drones in the sky was pre-recorded because of "possible freezing weather and strong winds".