Traffic soared at news, government and a few political Web sites this week after war erupted in Iraq, much of it coming from people surfing the Internet while at work, according to experts who measure Internet use.

The number of people visiting the Web's top news sites and a dozen federal sites ran at more than twice the usual rate Thursday, according to ComScore Media Metrix.

A Marines Corps site (www.marines.com) experienced the biggest spike, up 411 percent, to 30,534, visitors, ComScore reported.

The at-work audience reached 36.5 million people on Wednesday, almost matching the home audience of 37.1 million. Overall at-work traffic jumped 16 percent, while at-home traffic rose only 1 percent, ComScore reported.

"Without a doubt, people are glued to their Web browsers for virtually minute-by-minute updates of the war as it unfolds," said Daniel E. Hess, vice president of ComScore.

It's hard to measure overall traffic online, given that the Internet is a network of networks and not centrally managed. But one firm that distributes and manages traffic for more than 1,000 of the Internet's largest sites said the volume of data it moved reached an all-time high Thursday.

Akamai Technologies Inc. served 24.8 billion "hits," or requests for Web page elements, Thursday, roughly twice its average of a month ago, said spokesman Jeff Young. The data suggest people were using the Internet more intensely this week by calling up far more pages, he said.

Yahoo.com was among the places where usage skyrocketed -- the volume of traffic to its news section jumped 600 percent on Thursday and again Friday, said spokeswoman Sabrina Friedman. She said the amount of free audio and video that users chose to view rose tenfold.

Some of the largest traffic increases occurred at the Web counterparts to the broadcast and cable television networks, a fact Hess attributed partly to TV networks promoting their Web sites. Hess said the data suggest people are moving from watching their favorite networks on TV at home to viewing them on the Web once they get to work.

"The two media are playing tag team with each other," Hess said.

Among TV networks, FoxNews.com saw the biggest jump, up 218 percent Thursday over its average traffic for the past four weeks, ComScore found. CBSNews.com was next, with an increase of 207 percent; followed by CNN.com, up 200 percent. On Thursday, CNN.com had the most traffic of all the news sites: 9 million visitors. MSNBC.com was next, with 6.8 million.

A few military sites were hard to access at times this week, especially the Army's public site (www.army.mil), according to Keynote Systems Inc., which specializes in measuring the performance of thousands of Web sites. Keynote found that the Army's site was sluggish starting on Monday and suffered "severe problems" on Wednesday, remaining inaccessible to visitors at time. It improved on Thursday, Keynote said.

But Lt. Col. Mark H. Wiggins, Web director for the Army's public site, said internal computer logs showed its Web servers were not overloaded this week, even though the site's traffic was even higher than in the weeks after the Sept. 11, 2001, terrorist attacks.

Wiggins contended that any slowness visitors experienced stemmed from congestion on the Internet, not a lack of computing power at the Army site. The Army was already planning to expand capacity for its Web site before traffic jumped this week, he added.

Hess said one in four visitors to the government's top military and defense sites on Thursday was from overseas.

"Large numbers of people are coming to our virtual shores seeking information," he said. "It's an opportunity I hope the government is taking note of."

Traffic also jumped this week to antiwar Web sites, which have been coordinating peace protests for months. On average, three leading protest sites (www.antiwar.com; www.unitedforpeace.org; www.stopwar.org.uk) drew 160 percent more traffic than they did four weeks ago.