KABUL, Afghanistan (CNN) -- Afghan lawmakers have directly accused Pakistan's intelligence agency of involvement in a string of deadly attacks in Afghanistan, blasting their neighbor as "the largest center for breeding and exporting terrorism." The recent attack by a suicide bomber on the Indian embassy in Kabul killed more than 40 people. A Pakistani official Tuesday bristled at the accusation, saying that Afghan lawmakers were making allegations without proof. "We are not an irresponsible nation and we don't blame our failures on others," said a senior official with Pakistan's Directorate for Inter-Services Intelligence (ISI). "If they want to engage in this kind of game, let them be."
@highlight
Afghanistan: Pakistan is "largest center for breeding and exporting terrorism"
@highlight
Attacks carried out by Islamic militants have killed scores of people in Afghanistan
@highlight
Pakistan intelligence service often accused of orchestrating attacks
@highlight
Pakistan: Afghan lawmakers making allegations without proof
But @placeholder claims that Pakistan continues to informally support the militants, who operate from havens in Pakistan's lawless tribal regions near the porous 1,500-mile border the two countries share.