Updated

Members of the U.S. Navy were denied access to FoxNews.com for hours on Friday before service was finally restored shortly before noon ET, the Navy confirmed.

Cmdr. Danny Hernandez, a Navy spokesman, said he was unable to offer an exact reason why access to Fox News' Web site had been blocked, but he said it most definitely was a technical issue.

"This was not a policy issue," Hernandez said.

Fox News received e-mails from Navy personnel around the world on Friday complaining that they could not gain access to the Web site. They said they were able to view numerous other news Web sites.

When they tried to access FoxNews.com, the following message appeared: "Access to this site has been denied in accordance with Navy policy to safeguard the security posture and/or to maintain the operational integrity of the NMCI."

NMCI stands for Navy Marine Corps Internet.

Lt. Justin Cole, a Navy spokesman, initially told FoxNews.com Friday morning that "there's got to be some type of issue with NMCI." But later he said he had been informed that it was not an NMCI issue.

"It appears to be some problem with the network," he said. "From time to time, there are security issues that make sites go up or down according to the policy. I'm not sure what the cause of this outage is."

Cole said several sites were affected by the outage. He said there was "no concern" that the network had been hacked.

The outage could have occurred automatically or manually, Cole said. But if it was manual, he said he was not sure who would have made that decision.

"There's every reason to believe there's security issues with the Web sites themselves," he said. "We don't know why these decisions were made."

Marines at the Pentagon had access to FoxNews.com throughout the morning. But Navy members stationed in Europe also were denied access, according to a source.

The server for the Navy and Marines branches off at the Marine Corps base in Quantico, Va.

Maj. Carl Redding, a Marine spokesman in the Pentagon, said he had access to FoxNews.com all along but added that it's not surprising to him that folks in the Navy were being blocked and getting an error message. Although the Marines work on a different network, Redding said they get similar error messages all the time when trying to log on to legitimate Web sites.

"It's the nature of the network," Redding told Fox News, adding that he believed the blocked access was not intentional.

Fox News' Justin Fishel and FoxNews.com's Stephen Clark contributed to this report.