Five people were killed on Tuesday when a cargo plane carrying fuel for the UN's World Food Programme crashed near South Sudan's capital Juba, airport officials said.

The aircraft -- a Soviet-era Antonov An-26 transport plane -- crashed shortly after taking off from Juba's international airport, killing everyone onboard.

"One is a South Sudanese, two are Sudanese and two are Ukrainians," David Subek, head of the South Sudan Civil Aviation Authority, told AFP. 

The cargo plane belonging to a local operator was reportedly carrying 28 barrels of fuel for the WFP to Maban, a district housing more than 100,000 refugees. 

According to the airport's director general Kur Kuol, it hit a mango tree and caught fire. 

"The people on board were burnt. They are in bad shape," said Kuol.

South Sudan Red Cross said emergency workers had collected five bodies that were "burned beyond recognition".

South Sudan, a young nation that achieved independence in 2011 and has been in the throes of a chronic economic and political crisis, lacks a reliable transport infrastructure, with plane crashes often blamed on overloading and poor weather. 

President Salva Kiir on March 3 ordered the suspension of an airline after one of its planes crashed in the country's east, killing all 10 people aboard including the two pilots.

The aircraft belonging to South Sudan Supreme Airlines crashed in Jonglei state shortly after taking off from Pieri.

Another plane owned by local company South West Aviation crashed in August last year killing four passengers and three crew.

The cargo plane had been carrying cash to the Wau region in the country's northwest for Juba-based Opportunity Bank.

Overloading of planes is common in South Sudan, and was believed to have contributed to the 2015 crash of an Antonov plane in Juba that left 36 people dead.

In 2017, 37 people had a miraculous escape after their plane hit a fire truck on a runway in Wau before bursting into flames.