The Ethiopian government has freed 40 Western pilots arrested for violating its airspace.

The pilots crossed into the Ethiopian territory on 20 small aircraft on Tuesday.

They were taking part in a vintage plane rally when they entered Ethiopia from Sudan.

They were allowed to travel to Nairobi, Kenya upon their release.

“VintageAirRally crew are allowed to fly on from Ethiopia! Aviators who were detained in Ethiopia are now free to continue their journey.

"The adventure continues!,” the group posted on its Facebook page.

The Western pilots were detained on Tuesday for entering Gambela town- located in western Ethiopia bordering South Sudan, which has experienced civil unrest for close to three years.

“The Western pilots, who entered into Ethiopia with their 20 light aircrafts have been detained in Gambela for 'illegally' entering into the country and are under investigation,” the Director-General of the Ethiopian Civil Aviation Authority, Mr Wossenyeleh Hinegnaw, said Thursday afternoon.

Among the detainees were US and British nationals.

The US embassy said several of its citizens were among those arrested and that it was working with the government for detailed information and to have consular access.

Following Ethiopia’s declaration of state of emergency on October 8, 2016, the US Department of State "warned US citizens to defer all non-essential travel to Ethiopia due to ongoing unrest that has led to hundreds of deaths, thousands of arrests, as well as injuries and extensive property damage, especially in Amhara and Oromia States.” 

The planes, dating from the 1920s and 1930s, took off from the Greek island of Crete on November 12on a 13,000km (8,000 mile) journey to Cape Town.