Some ANC members walk out of Mandela Bay's first council meeting
Athol Trollip's election as mayor of the metro was greeted with cheers and ululations.
The UDM's Mongameli Bobani was also installed as the deputy mayor during the meeting.
Councillors have been warned not to jeer other members at this afternoon's sitting.
The Democratic Alliance (DA) secured 46.7 percent of the vote in this month's local government polls and entered into a coalition with the United Democratic Movement, Congress of the People and the African Christian Democratic Party to form a multi-party government in the hotly-contested metro.
As Trollip took his mayoral seat, there were cheers and ululation.
There was, however, also jeering and booing seemingly from ANC members and supporters at the Feather Market Hall where the inauguration ceremony was taking place.
As some ANC councillors left the venue, newly-elected Speaker Jonathan Lawack noted the walkout and asked that it be recorded.
The ANC's Litho Suka complained to Lawack that former mayor Danny Jordaan was excluded from proceedings.
It's understood Jordaan was among councillors who were stuck outside the council venue after doors were locked at 10am.