Mathunjwa was addressing about 5 000 Amcu members who celebrated Workers’ Day in Orkney, North West.
He claimed the National Union of Mineworkers (NUM) was responsible for the attack on Amcu members.
Amcu toppled the ANC-linked NUM at Lonmin in 2012 and became the major workers’ union, and this fuelled bad blood between the two organisations.
“Our members have been killed but no-one has been prosecuted,” said Mathunjwa.
“But if an Amcu member coughs in front of a NUM member, 50 police officers can come and that member will sleep in police custody.”
Mathunjwa said the government had not changed the lives of black people for the better since it came to power in 1994.
“Comrades, we voted and they said we would get free houses. What will you do with a free house if you are not working? No country can survive on handouts. They [ANC] were voted by us to lead this country, but we are the owners of this economy.”
He also appealed to South Africans to treat foreign nationals like their brothers and sisters and quell xenophobia.