South African police used stun grenades and a water cannon to disperse striking hospital workers in the port city of Durban yesterday as a crippling public sector strike entered its seventh day.

The pay strike has highlighted the ideological battle facing the ruling African National Congress as it prepares to elect a new leader in December, with unions saying President Thabo Mbeki?s business friendly policies have left millions behind.

The SAPA news agency said police in Durban moved against about 200 workers who they charged were blocking the entrance to the King George V hospital.

?They refused to move when we asked them and a decision had to be made,? Inspector Glen Nayager told the agency, adding that four people had been arrested and he was not aware of any injuries.

Workers at the scene told SAPA no warning was given before police used batons and stun grenades.

?They posed for the camera with their guns. Then next they were hitting us with their batons,? said one protester.