Chaos erupted at the City of Tshwane's headquarters and council chambers on Wednesday as protesting municipal workers threw bottles in reaction to Tshwane Mayor Cilliers Brink's announcement that the cash-strapped City could not grant workers wage increases.

Bottles were hurled at police after Brink announced that the City could simply not afford the R600-million it would have to fork out for the previously agreed to increases.

Brink and municipal manager Johann Mettler had organised to meet the South African Municipal Workers' Union (Samwu) at Tshwane House on Wednesday, but the meeting quickly turned violent.

A video Brink shared showed workers throwing the glass bottles at the police outside of the designated meeting area as police held up shields to block them and steered members of the public to safety behind trucks.

This is the second year workers in Tshwane won't receive a wage increase. 

According to Samwu provincial secretary Mpho Tladinyane, its members at the City planned to march on Wednesday after they didn't receive their promised increases.

"We were meant to be paid our salary increase today, and we have not been paid. The City owes us money from 2021... and that is why we have this action today," he said.

According to Samwu in Gauteng, workers raised issues about the non-payment of the 3.5% and 5.4% salary increases, the payment of annual once-off notch increase, and the unilateral implementation of the performance management system.

Earlier this year, Brink revealed that in 2019, workers received an 18% salary increase that was deemed irregular. The City could not afford to pay more.

On Wednesday, Brink pointed out the City's dire financial state, which influenced its 0% wage increase decision.

"We think these wildcat strikes and outages are in all likelihood related to the fact that the City has not budgeted for salary increases in the financial year.

"And because the municipal council resolved that the City should approach the bargaining council to ask for an exemption to these increases.

"The fact is, we would obviously like to pay increases to our people, to reward the hard work of officials, but the point is, in our present financial situation, we simply can't afford to.

"We would be paying in the region R600 million more in salaries if we were to grant these increases." 

Brink added that the City would execute a "rescue mission" to ensure the financial sustainability of Tshwane and save it from "financial ruin".

Brink's spokesperson, Sipho Stuurman, said there was ongoing engagement between Mettler and the municipal workers.