The Centre had forewarned the Karnataka and Andhra Pradesh governments that terrorists could target Bengaluru and Hyderabad, Minister of State for Home Sriprakash Jaiswal said on Friday.

"The Intelligence Bureau had received inputs that terrorists could target the cybercities of Hyderabad and Bengaluru. Both the state governments were told to be on high alert," he said.

Jaiswal said the main aim of the serial blasts in Bengaluru was to "spread terror".

The Centre is in touch with the state government and ready to offer all possible help, he said.

Meanwhile, a high alert has been sounded in Delhi on Friday after eight near-simultaneous blasts rocked Bengaluru during the busy lunch hour, resulting in the killing of one woman and injuring several others.

The Delhi police have deployed extra personnel at crowded areas like airport, railway stations and market places.

"The police have intensified checking and deployed extra personnel for vigil in the capital," Delhi police spokesperson Rajan Bhagat said.

"A high alert has been sounded in the capital as soon as the news about the blasts in Bengaluru was received," he added.

Requesting the public to maintain calm and not to panic, the Delhi police have appealed citizens to report any suspicious movement or object to its nearest staff or emergency call numbers.

The eight near-simultaneous blasts rocked the southern city of Bengaluru, leaving one woman dead and several persons injured.