Hyderabad: Polling for by-elections to seven Assembly constituencies in Andhra Pradesh started on Sunday morning amid tight security.

Six of these constituencies –- Kollapur, Nagarkurnool, Mahbubnagar, Kamareddy, Adilabad and Station Ghanpur -– are in Telangana region, while the seventh, Kovur, is in coastal Andhra.

Voting started at 8 AM and will continue till 5 PM. The total number of eligible voters is about 13 lakh.

State's Chief Electoral Office Bhanwar Lal had said that the election machinery had geared up for a smooth polling.

The by-elections to five of these constituencies were necessitated by the resignations of sitting MLAs in support of the separate Telangana demand. At Mahabubnagar, sitting MLA died, while in Kovur, the sitting TDP MLA quit in support of Kadapa MP Y S Jaganmohana Reddy.