The US military commander in charge of defending the US homeland said Tuesday that he believes there are al-Qaida cells in the United States or people working to create them. Air Force Gen. Victor "Gene" Renuart said that while the terrorism threat within US boundaries has increased in the past year, officials have strengthened intelligence sharing, particularly in an effort to shore up weaknesses in security at US ports. "I believe there are cells in the United States, or at least people who aspire to create cells in the United States," Renuart said in an interview with The Associated Press. "To assume that there are not those cells is naive and so we have to take that threat seriously." He added, "Am I concerned that this will happen this summer, I have to be concerned that it could happen any day."