Top U.S. military officials said Wednesday that Iraq is operating only five of its 66 airfields and 5 percent of its radar capacity.

But Gen. Colin Powell, chairman of the Joint Chiefs of Staff, and Defense Secretary Dick Cheney, refused to disclose the percentage of Iraqi installations destroyed by allied bombs in the past seven days or figures for those that Iraq may have closed for strategic reasons.They said such revelations could assist Iraqi President Saddam Hussein.

Both officials acknowledged that calculating the success rate of the 12,000 sorties flown by U.S-led forces in the first week of Operation Desert Storm has been hampered by cloud cover over the Persian Gulf region and a complex military analysis that is painstakingly slow.

"I want to caution you again that a military operation of this intensity and complexity cannot be scored every evening like a college track meet or a basketball tournament," Cheney said at a Pentagon briefing.

Powell called Saddam's decision not to aggressively use his formidable air force "vexing" and suggested the resourceful military leader may be delaying action to achieve the upper hand during ground combat.

Military reports indicated Iraq's radar detection has decreased by 95 percent since the war began. While U.S.-led forces are said to have destroyed many radar installations, it was unclear if Saddam had closed the facilities to deceive the allies.

Powell characterized Iraq's use of the Soviet-made Scud missile as an annoyance, not a real military threat.

"With the one exception of perhaps one (allied) airplane that may have been downed, the Iraqi Air Force has not been able to interfere with our air operations," Powell said.

Wednesday marked the first time since the operation was launched that both officials have briefed reporters on the status of the war. Although they were confident that bombing raids would squeeze Saddam's military and force the army out of Kuwait, Powell and Cheney were restrained.

During the briefing, the officials displayed several charts and graphs intended to give a clearer - though not precise - picture of allied successes and Iraq's military response.

Powell said Iraq had flown 41 sorties in each of the past two days while allies launched about 2,000 daily. The Iraqi sorties are being flown from five air bases in and around Baghdad, including the Baghdad International Airport, he said.

The Pentagon also identified two areas from which Scud missiles were launched in the northwest and southeast. The diagrams were too widely drawn to accurately identify launch areas.

Military officials say they believe allied forces have destroyed all or most of the fixed Scud launching sites.