Early state election results in the central state of Madhya Pradesh show a nail-biting contest between India’s ruling BJP and opposition Congress.
The leads show a late comeback for the BJP in the central state. Early results showed a clear lead for the Congress.
However, Congress is leading in Rajasthan and Chhattisgarh, which were previous BJP strongholds.
Correspondents say the losses are a predictable and likely temporary backlash against incumbent parties.
India will hold nation-wide parliamentary elections early in 2019.
Election results are also being declared for the southern state of Telangana and the northeastern state of Mizoram.
Regional parties – the Telangana Rashtra Samiti (TRS) and the Mizo National Front (MNF) – are leading in these states.
The Congress was widely expected to win in the northern state of Rajasthan, while the central state of Madhya Pradesh was always seen as a close contest between the two parties.
But early results in the central state of Chhattisgarh, where the Congress is ahead by a wide margin, have been the most surprising.
BBC Hindi’s Nitin Srivastava who is in Rajasthan, has been posting photos of the starkly different atmospheres at the BJP and Congress party offices in the state.
A shot in the arm for Congress?
Soutik Biswas, BBC News, Delhi
This is the last round of state polls before general elections, which are slated to be held in the next few months.
The Congress’s vastly improved performance in the three key heartland states will help change the perception that Mr Modi’s BJP is invincible, boost the morale of party workers and make the party more acceptable to sceptical regional allies in the run up to crucial general elections next year. It will also help raise the profile of the party’s leader, Rahul Gandhi, who led a spirited campaign in the three states.
In 2014, the BJP won 62 of the 65 parliamentary seats in these three states.
Tuesday’s performance will be a shot in the arm for the Congress which has been consistently losing state elections since 2014 – the party rules in only two major states.
But state polls are often a poor predictor for the general elections.
It will take a lot more – including a powerful counter narrative and wider voter acceptability – for the Congress to mount a serious challenge to Mr Modi next year.
The good news is that politics in India is beginning to look competitive again.