Truckers expected to block major routes

JOHANNESBURG - Truck drivers are threatening to shut down major highways around the country on Sunday.

They're upset over the employment of foreign nationals by local companies.

READ: Planned truck protest on Sunday

NATJOINTS -- which is made up of the police, defence force and State Security Agency -- is on standby.

It says it's mobilised all resources to prevent and combat any form of lawlessness.

READ: Truck driver protest | Clampdown on illegal foreign drivers

It's called on those taking part to do so peacefully.

There have previously been violent incidents at demonstrations over the same issue.