The motorcycle on which four perons were riding to Omalur was following a car which was moving behind a private bus when the mishap occurred at Mecherry, police said.
The bus driver suddenly applied brakes resulting in the other vehicles slamming into each other.
Under its impact, the motorcycle was hit from the rear by a lorry and the 57-year-old woman and nine-year-old girl were killed on the spot. Another person was seriously injured, they said.