Hyderabad, Nov 8 (IANS): A court in Andhra Pradesh's Chittoor district Thursday acquitted two of the four accused in the failed assassination attempt on former Chief Minister N. Chandrababu Naidu.

The fourth district court struck down the lower court's order sentencing Maoist leader Panduranga Reddy alias Sagar and gelatin stick trader Gangi Reddy. The court dismissed the case against them due to lack of evidence.

The court, however, upheld the seven-year sentence awarded to two other accused Ramaswamy Reddy and Nagarjuna, both gelatin stick traders.

In October 2010, Additional Senior Civil Judge had sentenced the four accused to seven years jail each and they had challenged the order in the higher court.

Naidu, then chief minister, his ministerial colleague B Gopalakrishna Reddy and two legislators were injured when the Maoists triggered a claymore mine blast at Alipiri in 2003 when they were on their way to the famous Hindu temple at Tirupati to make offerings.

Naidu's convoy had come under the attack, meticulously planned by the Maoists. However, the TDP chief survived with minor injuries.

Though the prosecution named 33 persons as accused in the case, only four could be arrested. Some of the accused, including top Maoist leader and prime accused Patel Sudhakar Reddy, were killed in alleged gun battles with police while others still remain at large.

Sudhakar Reddy, believed to be the mastermind behind the attack on Naidu, was killed by police in an exchange of fire in Warangal district in 2009.