The top brass of the NATO-led International Security Assistance Force (ISAF) blamed Pakistan-based insurgents for staging a 20-hour siege in Kabul on Wednesday. Gunfire began close to the U.S. Embassy on Tuesday morning, coinciding with blasts from improvised explosive devices. The attackers fired rockets at the U.S. Embassy, the ISAF command building and at Tolo TV. The siege ended on Wednesday leaving at least 16 people dead, including five Afghan police officers, 11 civilians and 6 children, according to ISAF commander Gen. John Allen. \"The complexity of the attack and the way in which it was executed suggest this was probably a Haqqani-instigated attack,\" Gen. Allen said at a press briefing. The Haqqani network is a group of roughly 3,000 fighters based out of North Waziristan in Pakistan and three of Afghanistan\'s eastern provinces. The network is a crucial ally of al Qaeda and has been a longtime asset of Pakistan\'s military and intelligence services in Afghanistan. Gen. Allen emphasized that the attack was a military failure but also a propaganda victory for the terrorists. He said the raid frightened Kabul residents and made headlines around the world. U.S. Ambassador to Afghanistan Ryan Crocker also downplayed the assault, saying the militants were only capable of what he called \"harassment,\" firing six rocket-propelled grenades at the embassy from a distance of 800 meters. No embassy staff members were wounded. The Haqqani have been blamed for high-profile attacks in Kabul and elsewhere in Afghanistan, including the bombing of the Indian Embassy in 2008, which killed 54 people.