A suicide bomb killed nine foreign workers and three others near the airport in Kabul.
The group claiming responsibility is angry over the anti-Islam video that sparked protests throughout the Muslim world.
Afghanistan has now blocked it on YouTube.
In Libya, a tribute to ambassador Chris Stevens: "Chris was able to help in protecting our city Benghazi, but Benghazi was unable to protect him." said Libyan Activist Salwa Begaighis.
The U.S. says Libyan authorities and the FBI are cooperating, but Libya is running the investigation into his death. "These are not the people who were demonstrating for democracy and overthrowing Ghadhafi. These are the people who were the loose one, the Al Qaeda type elements that are seeking to overthrow what has been achieved," said Former Secretary of Defense: William Cohen.
Meantime., anti-American protests around the region continue, with some countries unable to protect our embassies: "We had governments that had a lot of will to protect us but may have overestimated the capability of the forces that they had around, and had to augment," said Victoria Nuland State Department Spokeswoman.