About 13 per cent votes were cast in the first three hours of polling in Andhra Pradesh where balloting was on in 22 Lok Sabha and 154 assembly constituencies on Thursday.
The polling booths opened at 7 am but the voting process was delayed in several centres due to non-functioning of electronic voting machines (EVMs).
"There were complaints from 40 to 50 places that EVMs were not functioning but the problem was rectified," state chief electoral officer IV Subba Rao told reporters.
By 10 am 13 per cent voter turnout was recorded. Barring minor incidents, the balloting has been peaceful.
Polling came to a halt in 19 polling centres in Aiza area in Alampur assembly constituency in Mahabubnagar district when some people damaged the EVMs and attacked the election staff and policemen.
Officials said the locals were protesting against the inclusion of their area in Alampur constituency in the delimitation process. Rao said re-poll would be ordered in the area.
Over 31.2 million voters, half of them women, are eligible to decide the fate of 2,148 candidates - 315 for the Lok Sabha and the others for assembly polls.
Hyderabad and nine other districts in Telangana as well as three districts of north coastal Andhra bordering Orissa went to polls in the first phase.
The polling will conclude at 4 pm as the authorities have reduced the time by one hour due to security reasons. Four helicopters were used to ferry men and material to inaccessible areas.
More than 60,000 policemen and 123 companies of paramilitary forces have been deployed.
Though the Maoist movement has considerably weakened in the state, the authorities are not taking chances. The police are on high alert, especially in areas bordering Chhattisgarh and Orissa.
The ruling Congress party and the four-party Grand Alliance led by the Telugu Desam Party (TDP) are locked in a neck and neck battle in constituencies going to polls in the first phase. The Praja Rajyam party of superstar Chiranjeevi is the third major political force.
The prominent candidates for Lok Sabha elections include union ministers S Jaipal Reddy, Renuka Chowdary and D Purandareswari, Telangana Rashtra Samiti (TRS) president K Chandrasekhara Rao, actress Vijayashanti of TRS, TDP leader K Yerran Naidu, Communist Party of India (CPI) national secretary S Sudhakar Reddy, Praja Rajyam vice president T Devender Goud and state Bharatiya Janata Party (BJP) president Bandaru Dattatreya.
The key candidates for assembly elections include state Congress president D Srinivas, assembly speaker KR Suresh Reddy, former bureaucrat and Lok Satta president Jaiprakash Narayan, actress Jayasudha of Congress, actor Babu Mohan of TDP and several state ministers.
Chiranjeevi and his family members, TRS president K Chandrasekhara Rao, Vijayshanti, chief electoral officer Subba Rao, Director General of Police AK Mohanty and several others cast their votes in Hyderabad.
Popular actor and TDP star campaigner Junior NTR came to a polling booth on a stretcher and cast his vote. The star, who was injured in a road accident, reached the centre in an ambulance. His uncle and popular actor Balakrishna also voted there.
The second phase of polls on April 23 will cover 20 Lok Sabha and 150 assembly constituencies in south coastal Andhra and Rayalaseema.