President George W. Bush and officials raised the national terror alert Friday afternoon, but the change won't affect the plans for this weekend's NBA All-Star Game in Atlanta, according to commissioner David Stern.

Stern reiterated Friday that the NBA is already prepared for any security breech, having "worked with all agencies to secure the buildings."

The All-Star festivities begin Saturday at Philips Arena with the Rookie and Skills challenges, 3-Point Shootout and the Slam Dunk Contest. The All-Star Game is Sunday at 8 p.m. ET.

"It's a fact of life now," Stern told ESPN on Friday. "Bags will be searched … We'll do everything so guests can feel secure in a fun environment."

A senior administration official said the decision to raise the alert to orange, the second highest level, was based on an increase in intelligence pointing to a possible attack around the Muslim holy period of the Hajj, the annual Muslim pilgrimage to the holy Saudi city of Mecca.

The terror alert has been at code yellow, or "elevated,'' which is the middle of a five-point scale of risk developed after the Sept. 11, 2001 attacks. It was last raised to orange in September and stayed there for two weeks to coincide with the first anniversary of the attacks. The highest alert level is red.

The reasoning behind Bush's decision was unclear early Friday. One U.S. official said there was no specific threat made, but the increase in chilling U.S. intelligence -- much of it corroborated -- led the administration to determine that there was sufficient reason to put Americans on notice.

U.S. preparation for a possible war with Iraq and Sunday's start of the Hajj were also key factors in the decision to raise the alert status. Muslim holy periods tend to raise jitters about terrorist activity among U.S. intelligence officials.

Stern added Friday: "(The alert) doesn't effect us, because we've already been prepared."

The Associated Press contributed to this report.