Traffic came to a standstill on the N1 freeway, following collisions between passenger vehicles and trucks, emergency services said on Thursday.

Netcare 911 spokesperson Mark Stokoe said two trucks collided at the Atterbury off-ramp resulting in 10 vehicles and three trucks crashing at the Rigel off ramp in the early morning traffic.

He said five people were seriously injured in the Atterbury accident, but were taken to hospital in a stable condition.

Meanwhile, in the Rigel off-ramp accident, Stokoe said that a bakkie carrying five people rolled into a ditch and a truck landed on top of it.

"The road is under construction where the second accident happened. Two bakkie occupants have been confirmed dead, another is critical, two others are seriously injured but stable.

"The fire fighters are removing the truck in stages to free the remaining two," he said.

Tshwane metro police had attempted to divert cars, but there was "chaos".

"Only one lane has been opened for traffic, but it will take a while to clear the scene," said Stokoe.