Cabinet has condemned the displaying of South Africa's apartheid-era national flag during mass protests by farmers on Monday.

"Cabinet has condemned the blocking of public roads, displaying of symbols of past oppression and destruction of national symbols which are a reflection of our hard-earned democracy," it said in a statement following its regular fortnightly meeting.

Communications Minister Mmamoloko Kubayi told a post-Cabinet media briefing there was at this stage no plans to ban the apartheid-era flag.

"We have not gone to the extent of saying we must ban.... it is part of history. If we did, we would have to look at whether it is in the best interest of nation building," she said.

Monday's protests were a response by the farming community against the high incidence of killings of farmers and farm workers. Minority rights group Afriforum claims 74 people have been killed in attacks on farms so far this year.