Mild tremors were felt in Upputhara and Peerumedu taluk areas of Idukki district on Friday, leaving cracks in some houses.
The magnitude of the first tremor at 5.27am was 2.8 on the Richter Scale, while the second at 5.45am was of 3.2 magnitude, collectorate officials said.
Cracks developed in the walls of some houses in the two areas after the tremors.
The area also homes Mullaperiyar Dam, but it was not immediately known whether the dam was affected by these mild tremors.