The US has increased airport screening in the wake of the failed Christmas Day attack, prompting concerns over racial profiling. A Canadian Muslim woman has come forward with allegations she was harshly treated while trying to enter the United States last week. Ayat Manna says she was picked out of a line and questioned by US customs agents at Halifax International Airport on her way to visiting her husband in Ohio. Manna says she was refused entry after a four-hour interrogation. In an interview with Canadian television, Manna said she believes she was singled out for wearing the traditional Muslim headscarf.