Mizoram Chief Minister Lal Thanhawla resigned on Tuesday evening following the debacle by Congress in the assembly election and admitted that he had "underestimated" the opposition strength.
The five-time chief minister said he also underestimated the "extent of the anti-incumbency wave".
Thanhawla had been at the helm of the government in the northeastern state for two consecutive terms since 2008.
His resignation was accepted by Governor Kummanam Rajasekharan who asked him to continue in office till alternative arrangements were made.