Mozambique opposition leader Venancio Mondlane returned home on Thursday, after fleeing in the days following a hotly contested October election that sparked demonstrations in which scores of protesters have been killed.

Mondlane says the Oct. 9 polls were rigged and has called on his supporters to take to the streets across the southern African nation of 35 million.

A heavy riot police presence was felt in the areas surrounding the capital Maputo’s international airport where thousands gathered to welcome Mondlane.

Frelimo has ruled Mozambique since the end of the war against Portuguese colonial rule in 1975, clinging on throughout a 15-year civil war that killed a million people before a 1992 truce.

Last year’s unrest hurt businesses and disrupted border access with neighbouring South Africa, while some people have fled to neighbouring Malawi and Eswatini amid the violence.

Mozambique’s top court in December confirmed the ruling party Frelimo’s election victory – despite multiple reports from observers that it was not free and fair – triggering a fresh round of protests.