The Andhra Pradesh government suspects the attack on Chief Minister N Chandrababu Naidu's convoy near Tirupati was the handiwork of the outlawed People's War group of Naxalites.

Also see: Assassination bid on Andhra Pradesh CM

"It was a mindless and coward act," Home Minister T Devender Goud told reporters in Hyderabad on Wednesday. Six Claymore mines were planted on the road and triggered one after the other, he said. But reports from the spot said there were only two blasts.

Naidu topped the hitlist of the Naxalites ever since he re-imposed the ban on the group in July 1996. Since then, the Naxalites had stepped up their violence, thereby inviting a no-holds-barred counter-offensive from the state police, resulting in several killings on both sides. But this is the first time they made a serious bid on the chief minister's life.

The attack comes in the backdrop of the spurt in Naxalite activities in the Nallamala forest along the Krishna River, particularly in Kurnool and Anantapur districts in the Rayalaseema region and in Guntur and Prakasam districts in south coastal Andhra. These areas had largely remained free from Naxalite violence till a couple of years ago.

Their activity was concentrated in the Godavari basin region comprising the Telangana region and the north coastal districts.

The violent movement of left-wing extremists took birth in the forests of the northernmost coastal district of Srikakulam neighbouring Orissa. But as the pressure from the police, particularly the anti-extremist commando force - known as Greyhounds - mounted, the Naxalites shifted base to the southern parts, which hitherto had served only as a sanctuary.

Police officials point out that last year, the Naxalites had triggered a landmine explosion killing a few policemen in the Telangana region just before the chief minister's visit. At that time, police believed Naidu was the actual target.

The site of the latest attack, the ghat section between Tirupati town and the Tirumala temple complex on the seven hills, is supposed to be a high security zone with fool-proof security arrangements in place, particularly after the terrorist attack on the Akshardham temple complex in Gujarat.

In the last one decade, the Naxalites have in the past killed several people's representatives, including sitting Congress MP Magunta Subbarama Reddy, Congress MLAs D Raghya Naik and S Chenna Reddy, Telugu Desam Party MLA Palvai Purushottam Rao, former deputy speaker D Sripada Rao, besides at least two former MPs and half-a-dozen former MLAs. In all these incidents, the victims were shot dead.

Following the killing of three top PW group functionaries, including Nalla Adi Reddy, in December 1999, the Naxalites retaliated by killing the then panchayat raj minister A Madhava Reddy in a landmine blast at Ghatkesar near Hyderabad in March 2000. He was the first and only minister killed ever since the Naxalite movement began in Andhra Pradesh 35 years ago.

According to police sources, the PW group has targetted numerous local functionaries of political parties. During 1999-2002, it had killed as many as 74 political functionaries, including 43 belonging to the TDP. In the same period, 122 policemen lost their lives, mostly in landmine blasts, while 415 Naxalites were eliminated.