JOHANNESBURG (AP) — South African President Jacob Zuma was jeered by labor unionists and his speech was cancelled after scuffles broke out between his supporters and workers chanting for him to step down at a May Day rally on Monday.

Zuma, who is facing calls to resign after a string of scandals, was expected to call for unity between his ruling party, the African National Congress, and labor unions at the event in Bloemfontein but groups in the crowd booed him and clashed with his supporters before he could speak.

All speeches were cancelled by the Congress of South African Trade Unions, the country's largest body of unions, which has called for Zuma to resign.

Zuma, 75, once a popular figure among South Africa's workers, was eventually ushered away by his bodyguards.