Two days before the Hyderabad blasts, the Centre had alerted all states that Pakistan-based terrorist groups may carry out attacks in a major city to avenge the hanging of Ajmal Kasab and Afzal Guru.
Sources said the central security agencies had sent an advisory on Tuesday asking all states to tighten security in sensitive places as Lashkar-e-Tayiba, Jaish-e-Mohammad and Hizbul Mujahideen may launch attacks.
The security agencies sent another advisory on Wednesday saying banned Indian Mujahideen too may carry out terror attacks to avenge the hanging of Kasab and Afzal.
Union Home Minister Sushilkumar Shinde, without disclosing details, Thursday said that all states were alerted about a possible terror strike by militant groups.
However, Andhra Pradesh Chief Minister Kiran Kumar Reddy said these were general alerts and keep coming often.
