A clumsy Secret Service agent provided proof Friday that President Bush's bodyguards are carrying gas masks like the ones being given combatants in the Persian Gulf to guard against a nerve gas attack.

But a White House official said the president's security force was only worried about the possibility of tear gas during an anti-war demonstration rather than a chemical attack on Washington.The gas masks' existence came to light when a Secret Service agent dropped one onto the lawn from a green canvas bag.

In other gulf-related developments:

- Censorship: Reuter correspondents and photographers covering the gulf war from Iraq, Saudi Arabia and some other parts of the gulf are now subject to censorship.

Iraq has started censoring foreign press reports sent from Baghdad. U.S., British and French authorities have imposed military censorship on journalists in Saudi Arabia and other parts of the gulf.

- Costs: The first two days of Operation Desert Storm could cost as much as $1 billion, largely because of the high price of the ammunition being used against Iraqi forces, a defense analysis group said Friday.

A major chunk of the money spent so far has been for the Tomahawk cruise missiles launched in the initial phase the multinational military operation mounted against Iraq. The group estimates each 20-foot weapon - highly effective in reaching targets - carries a $1.35 million price tag.

- Holy war: Saddam Hussein is wrapping himself in the mantle of Islam, but U.S. Muslim leaders said there is nothing holy about either Iraq's invasion of Kuwait or the allied military response.

Some Muslim officials Friday called for a cease-fire and a resumption of negotiations amid warnings that Saddam's decision to fire missiles at Israel brings the world closer to a conflagration in the Middle East.

- High tech: The videotapes of air strikes on Bagdhad speak not only to the effectiveness of U.S. high-technology weapons, but also to their ability to give a bird's eye view of the Iraqi capital.

The detail on the tapes was so good that, as buildings exploded, automobiles could be seen moving slowly through the streets.

- Ground troops: While the world focuses on the air and missile battles in the Persian Gulf, there has been discernible movement of allied troops along the Kuwait border.

Most notable is the 101st Airborne Division - the Screaming Eagles - a highly mobile combat division likely to be among the first U.S. troops into combat.

The sabbath: Israel's chief rabbis appear to have found a way around a dilemma facing ultra-Orthodox Jews: how to observe strict Sabbath laws while protecting against an Iraqi missile attack.

Jewish law forbids even simple physical activities during the Sabbath, such as turning on the radio. But regulations may be overruled to save lives.

The rabbis said it's all right to leave the radio running on low volume during the Sabbath.