President Bush is demanding that those responsible for the assassination of Benazir Bhutto be brought to justice.

Bush spoke to reporters at his ranch in Crawford, Texas Thursday morning, after the death of the former Pakistani prime minister who's been a leader of the opposition to President Pervez Musharraf.

Bush said the U.S. "strongly condemns" what he calls a "cowardly act by murderous extremists who are trying to undermine Pakistan's democracy."

He says, "Those who committed this crime must be brought to justice."

Bush expressed his condolences to Bhutto's family and to the families of others who were killed and to the people of Pakistan.

He called on them to honor Bhutto's memory by, in his words, "continuing with the democratic process for which she so bravely gave her life."