Republican presidential candidate Sen. John McCain, R-Ariz., makes a point during a campaign event in Fresno, California, 23 Jun 2004

Republican presidential candidate John McCain has rejected a comment from a top aide, who said a terrorist attack on the U.S. would boost the senator's chances of winning the November election.

McCain said Monday in the western state of California he could not imagine why political adviser Charlie Black would make such a comment, adding that it was not true.  The veteran Arizona lawmaker said he has worked tirelessly since the September 11, 2001 terrorist attacks to prevent another attack on the United States.

A spokesman for presumptive Democratic presidential nominee Barack Obama called Black's remark "a complete disgrace."

Black has apologized, saying he deeply regrets the comments, which he called inappropriate.

He told Fortune magazine a new terrorist attack on the United States would be a "big advantage" because it would highlight McCain's foreign policy experience.  He also said the assassination of Pakistani opposition leader Benazir Bhutto "helped" for the same reason.

Meanwhile, a prominent Christian evangelical leader has accused Obama of distorting the Bible.

James Dobson, the founder of the Christian group Focus on the Family, criticized Obama for asking whether passages in the Bible about slavery and prohibitions against eating shellfish should be the ones to guide public policy.  Dobson said those references in the Old Testament no longer apply to the teachings of Jesus in the New Testament.

Campaign officials say Obama remains committed to reaching out to people of all religions.

The Illinois senator is to talk about his energy policy at a campaign event Tuesday in Las Vegas in the western state of Nevada, while McCain attends a briefing on the environment in California. 

Some information for this report was provided by AP and Reuters.