"We have demonstrated that the university cannot operate without our members," said David Dickenson of the Academic Staff Association of Wits.

The security boom gates at Wits University were unmanned and open and at least one university library was closed.

The one-day strike follows a breakdown of negotiations between unions and Wits management.

The academics are arguing that Wits has not lived up to the agreement to pay researchers competitive salaries.

National Education, Health and Allied Workers Union (Nehawu) Wits chairman Richard Sidiki said his members wanted a nine percent increase for the lowest paid staff member.

Sidiki showed reporters his own payslip that showed he earned only R3000 a month as his basic salary.

Several hundred staff members gathered outside the Wits Great Hall for a demonstration in support of the strike.

Wits vice chancellor Loyiso Nongxa watched the demonstration from the sidelines.

He told Sapa the university had been negotiating with unions when they walked out abruptly.

"They decided to walk out," Nongxa said.

He said the unions and management had already agreed on 98 percent of their issues.

Nongxa said management was also concerned about how the strike would damage the university's reputation.

"I am concerned about our reputation, but we cannot be coerced into something that is unsustainable," he said.