The Telangana Rashtra Samiti (TRS) is leading in 11 constituencies and the Bharatiya Janata Party (BJP) in one as the counting of votes in the by-elections to 12 assembly seats in Andhra Pradesh's Telangana region began Friday morning.

Early trends show the two parties may retain their seats while the TRS has also established lead in one constituency held by the Telugu Desam Party (TDP).

At the end of the first round of counting, TRS candidates were leading over their nearest rivals in 11 constituencies. BJP's Lakshminarayana was ahead of state Congress chief D. Srinivas in Nizamabad Urban segment.

The results from seven constituencies, where electronic voting machines (EVMs) were used, are likely to be announced before noon while it may take some more time in the remaining five constituencies where ballot papers were used.

The Election Commission said 66.67 percent of 23.60 lakh voters in the 12 constituencies spread over five districts cast their votes in the elections held Tuesday.

The by-polls were necessitated by the resignation of all 10 legislators of the TRS and one each of the BJP and the TDP on the issue of a separate Telangana state early this year.

As many as 435 candidates are in the fray for the by-elections, seen as a referendum on the issue of a separate Telangana.