On the eve of the second phase of polling, naxals on Wednesday carried out a string of attacks in Jharkhand, Bihar and West Bengal, including hijacking a a train with almost 700 passengers.

In West Bengal, naxals triggered four landmines in Salboni when security personnel went to fetch bodies of political workers killed by them on Monday.

In New Delhi the home ministry carried out a security review of naxal-affected states of Bihar, Jharkhand, Madhya Pradesh, Orissa and Andhra Pradesh, which are going to the polls on Thursday.

But there was no comprehensive strategy to ensure that phase II will be peaceful.  A day earlier, the Indian army brass discussed the naxal issue.

Over 50 security personnel and many civilians have been killed in naxal attacks, since elections were announced on March 2.

The attacks are clear signs that the threat is turning this staggered election into probably the bloodiest polls the country has ever witnessed.