Operations have been suspended at Kenya's main airport after thousands of mourners turned out to receive the body of former Prime Minister Raila Odinga, a day after he died in India.

Large crowds of mourners carrying twigs and palm branches breached security at Jomo Kenyatta International Airport (JKIA) immediately after the body of the former leader arrived on Thursday morning.

Authorities said mourners gained access to restricted areas, prompting a 'precautionary closure' to allow security teams to restore order and ensure safety.

Members of the public and travellers are advised to remain calm and avoid the airport area until further notice, the aviation agency stated.

Because of the unexpectedly huge crowds, the public viewing ceremony for his body has been moved to Nairobi's Moi International Sports Centre, rather than inside Parliament.

The 80-year-old former prime minister collapsed during a morning walk in India on Wednesday morning and was taken to Devamatha Hospital, where he suffered a cardiac arrest and was declared dead.

Kenyan politicians and international leaders are expressing their condolences, with President William Ruto calling Odinga a 'beacon of courage' and declaring a seven-day mourning period along with plans for a state funeral.