Days after declaring that it had foiled an attempt by al-Qaeda in the Arabian Peninsula (AQAP) operatives to blow up a US passenger plane, the US has vowed to go after them "wherever they are and wherever they try to hide". "As I've said time and time again, that we will go after al-Qaeda wherever they are and wherever they try to hide. And one of the places that they clearly are located is Yemen," US defence secretary Leon Panetta said at a Pentagon news conference yesterday. Both military and intelligence communities of the US have gone after al-Qaeda and will continue to do so, he said in response to a question about recent threats that emanated from Yemen. "The recent threat that concerned all Americans about the possibility of another effort to take down an American airliner has come out of Yemen. It's for that reason that we will continue to take all of the steps necessary to try to go after those who would threaten our country and threaten the safety of American people," he said. "We have operations there. The Yemenese have actually been very cooperative in the operations that we have conducted there. We will continue to work with them to go after the enemies that threaten the United States," he said. Pannetta's comments came days after officials said the US foiled an attempt by al-Qaeda in the Arabian Peninsula to blow up a passenger plane and seized a sophisticated explosive device bearing the "hallmarks" of the 2009 underwear bomb. The officials had said that a non-metallic explosive device that could have passed through airport security unnoticed like the one used in the failed attempt to bomb a Detroit-bound jet in 2009 by underwear bomber Umar Farouk Abdulmutallab was recovered. Panetta, however, on Thursday ruled out using US ground forces in Yemen to go after al-Qaeda there. "There's no consideration of that. Our operations now are directed with the Yemenese going after al-Qaeda," he said. The defence secretary said America's efforts in Yemen have been directed at the leadership of al-Qaeda and those who have been involved in trying to plan attacks on the US. "With regards to our efforts and our operations, we have been very successful at going after the leadership and those that are directly involved with regards to trying to make those kinds of plans. And I think the fact that we continue to be successful with regards to these kinds of threats is an indication of the effectiveness of the operations that we have there," he said. The al-Qaeda in Arabian Peninsula (AQAP), he said, does represent a threat in Yemen, and the Yemenis are the ones trying to make efforts to reduce their influence as well. "But they (al-Qaeda) are a threat. No one in any way underestimates the fact that all of them represent a concern for the United States in terms of our national security. But I do believe that we are making effective progress at going after those specific targets that represent real threats to the United States," Panetta said.