The Asian Network for Free Elections says issues led to the announcement of some preliminary results that were "wildly inaccurate."
An international election observation group has issued a critical report on Thailand's first election since a 2014 military coup, saying the "tabulation and consolidation of ballots were deeply flawed.
The Asian Network for Free Elections says those issues led to the announcement of some preliminary results that were "wildly inaccurate."
It says the inaccuracies damaged the "perceived integrity of the general election."
Thailand's Election Commission has defended the count and said full preliminary results will be released Friday.
Tuesday's comments from the observers come as a military-backed party and the party whose government was ousted in the coup both claim they should form the next government.
Preliminary results show the anti-military party won the most seats, while the military party appears to have gotten the most votes in Sunday's poll.