Bus drivers went on strike across Victoria this week as part of their fight for better pay.

Transport Workers Union (TWU) members who drive buses for CDC Victoria gathered at 4:00am on Tuesday for the first industrial action of its kind in 20 years.

The 24-hour strike was in response to CDC’s offer of a wage increase of 2.5 per cent.

The union wants a 4 per cent rise.

The strike hit Ballarat's bus network, half of the bus network in Geelong, as well as parts of Melbourne's east and west including the Oakleigh, Sunshine and Wyndham depot bus routes.

Many potential passengers only found out their bus would not be coming by reading notices stuck on signs at bus stops. Reports say that that not all stops on all affected routes carried the notices, suggesting some people would have been left in the dark.

TWU national vice president John Berger said members overwhelmingly support the strike action.

“We don't take that action lightly so we apologise to the general public,” he said.

Mr Berger said industrial action will continue on Friday and next Tuesday if the dispute cannot be resolved.

The union says drivers currently make between $26 and $28 an hour.

CDC Victoria apologised for the “significant disruptions”.

“Our drivers do a very important job and we feel this wage offer demonstrates our support for them,” CDC Victoria chief Nicholas Yap.

“I believe what we've put on the table is a fair and reasonable offer.

“We are working very hard trying to ensure they [the drivers] don't disrupt our customers, especially with school going back next week.

“We are mindful that we don't want any children to be left by the side of the road.”

The Victorian Government encouraged both sides to resolve the situation soon.