The senior-most military officer in the United States has accused Pakistan’s intelligence agency of supporting last week’s attack on the U.S. embassy in Kabul, Afghanistan. Adm. Mike Mullen, speaking to a panel of American senators, said the Haqqani network that carried out the attack is “a veritable arm of Pakistan’s Inter-Services Intelligence Agency.” Pakistan has firmly denied the alleged connection, saying that Mullen’s statement was “irresponsible.” At least 25 people died during the Sept. 22 attack, including 11 civilians. The ordeal lasted 20 hours, as insurgents attacked NATO headquarters and the U.S. embassy in Kabul. Mullen also told the Senate panel that there is “credible intelligence” suggesting the Haqqani network was also behind the high profile attack on Kabul’s Intercontinental hotel in June. The Haqqani network has close ties to the Taliban in Afghanistan, but is thought to have roots inside Pakistani territory.