The US has expressed concern over the bombings in Islamabad and Afghanistan and said that Pakistan is not involved in Kabul suicide bombing, State Department acting spokesman Gonzalo Gallegos told reporters.Gallegos said US will continue to work with the new elected government in Islamabad in fighting the common enemy of terrorism, while letting Pakistanis make their own decisions."We'll continue to work with the Pakistani government to fight our common enemy, which is these terrorist extremists who are willing to kill Muslims, Christians, anybody who gets in the way of the path which is what they seek, which is instability and chaos, so that they can prosper under that realm," he said.