The South African Federation of Trade Unions (Saftu) has called on the police investigators to leave no stone unturned in arresting the people who killed Bongani Cola at his home in Port Elizabeth on Thursday morning.

Cola, 43, was the deputy chairperson of the federation's affiliate, the Democratic Municipal and Allied Workers Union of SA (Demawusa) in the Nelson Mandela Bay Municipality.

Police spokesperson Capt Andre Beetge said Cola was taking his vehicle out of his home in Raxa Street in New Brighton just after 7am.

"Two shots were heard by people inside his home. When they came out, they found the deceased shot in the stomach and the lower shoulder. He died at the scene," Beetge said.

Zwelinzima Vavi, general-secretary of Saftu, said Cola was brutally killed as he was leaving home for work by unknown assailants who shot him as he was closing his garage.

"They did not take his car, which was idling outside the yard; they did not take anything in the car or from him. They shot him twice and left him in the pool of his blood," Vavi said.

Vavi said Saftu, which was formed after Vavi was ousted from another federation Cosatu, had lost count of its activists who had been assassinated in the Nelson Mandela Metropolitan area.

“This region has long become the silent killings fields of South Africa. There is hardly anyone who has been arrested and put on trial for all these estimated more than 20 killings,” Vavi said.

Vavi said Cola, together with a core of activists all of whom were former Cosatu-aligned South African Municipal Workers’ Union activists, had been making progress in recruiting workers for Demawusa in Nelson Mandela Bay.

"This undoubtedly would have angered the enemies of genuinely progressive, independent, democratic, campaigning and socialist-oriented forces.  He became a threat to the status quo, and he had to be eliminated."

Vavi also called on police minister Bheki Cele to personally intervene and appoint a special task team to investigate not just the assassination of Cola but all the other killings.