Williamnagar: Union home minister Rajnath Singh said on Monday that the killing of NCP's Williamnagar candidate Jonathone N. Sangma, 42, portrayed utter chaos and lawlessness in Congress-ruled Meghalaya.

Addressing an election rally at Songsak in East Garo Hills, Rajnath said, "The attack on the NCP candidate is a testimony that (chief minister) Mukul Sangma has failed to provide security to the citizens of Meghalaya."

Benjamin Marak, an eyewitness who was in a car behind Jonathone's white Scorpio, said the culprits could have been lying in wait for the convoy. "It was an ambush, a pre-planned strike," he said, recounting how the bomb ripped into the SUV in which the NCP candidate was travelling as it reached Sawilgre village under Samanda block in East Garo Hills district.

Deputy commissioner Ramkumar Singh said there were six others with Jonathone in the vehicle, of whom three were killed on the spot while three were injured. The victims have been identified as policeman Shamin Hassan, 30, Cribinath D. Shira, 38, and Baichung Ch. Momin, 40, a former member of the Garo National Liberation Army.

The critically injured, Silman N. Sangma, 45, Noor Abdul Miah (Jonathone's personal security officer) and Behensing Marak, 57, have been admitted to Downtown Hospital, Guwahati.

Ramkumar said no one had claimed responsibility for the attack. "Apart from finding the miscreants, we are investigating some posters of threat (to voters) at Samanda, Damagre, Nengkhra and other areas," he said.

Benjamin said Jonathone had visited Samanda to allay fears of the electorate so that they do not bow down to militant diktat. However, while returning, the blast accurred.

Senior Meghalaya police officials suspect the hand of banned GNLA in the blast.

NCP's Meghalaya unit president Saleng Sangma urged the government to institute an inquiry. Asked who will replace the candidate, he said it was "too early to say".

Social welfare minister and Congress candidate for Williamnagar, Deborah C. Marak, termed the incident "very unfortunate" and expressed her condolence to the bereaved family. She condemned the attack and sought a CBI probe.

Meghalaya's chief electoral officer Frederick Roy Kharkongor said a report on the attack had been sent to the Election Commission and more forces sought in western Meghalaya, comprising Garo hills and encompassing 24 of the 60 Assembly seats.

Polling in Williamnagar, where Jonathone was pitted against eight others, has been deferred. The next date of polling will be announced in due course, Kharkongor said. "In a meeting with top police officials we agreed that more companies of central paramilitary forces are required in Garo hills for fair and free elections to be held," he added.

A peace procession was taken out in the town on Monday and the market remained shut. It will also remain closed on Tuesday morning.