New Delhi has rejected allegations of a role in a suicide attack, calling them an effort to "concoct false narratives"

India has denied Pakistani allegations of involvement in a suicide bomb attack outside a district court complex in Islamabad that killed at least 12 people on Tuesday.

A day earlier, an explosion had left more than a dozen dead in Delhi.

Pakistani Prime Minister Shehbaz Sharif linked the Islamabad blast to other recent attacks in the country, saying on Tuesday that they were the worst examples of "Indian state terrorism" in the region. He also called on the world to "condemn such nefarious conspiracies of India."

Reacting to Sharif's allegations, Indian Foreign Ministry spokesman Randhir Jaiswal called the charges "baseless and unfounded," and described the Pakistani leadership as "obviously delirious."

"It is a predictable tactic to concoct false narratives against India in order to deflect attention of its own public," Jaiswal said on Tuesday. "The international community is well aware of the reality and will not be misled by Pakistan's desperate diversionary ploys."

The Islamabad blast occurred while the Sri Lankan cricket team, the target of an armed attack in March 2009 by gunmen in Pakistan, was playing a match in Rawalpindi, barely 10 miles from the court complex.

Pakistani Defense Minister Khawaja Asif claimed the Islamabad attack was orchestrated from Afghanistan.

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"We are in a state of war," Asif said on Tuesday. "Bringing this war to Islamabad is a message from Kabul, to which Pakistan has the full power to respond."

India has not blamed Pakistan for the Monday attack in Delhi, where an explosion in a car near the historic Red Fort left 13 people dead and injured over 20 others. Indian Home Minister Amit Shah has said security agencies were probing "all angles" and would "hunt down each and every culprit behind this incident."