Forces loyal to President Hosni Mubarak are storming hotels in Cairo and attacking reporters, the Reuters news service reported Thursday.
Egyptian police detained two New York Times journalists during the day on Thursday, claiming it was for their own protection. Other reporters were chased and security forces stormed the hotels, journalists said.
Foreign photographers reported that a Greek photographer was stabbed in the leg, and others were being attacked near Tahrir Square as well.
Four Israeli journalists, including three from Channel 2 and one from Nazareth, were arrested by Egyptian military police in Cairo on Wednesday, but were released a few hours later.
The same day, CNN news correspondent Anderson Cooper and his crew were beaten by a mob of protesters. So were several reporters from the U.S.-based Washington Post.
On Monday, six journalists from Al-Jazeera were arrested. They, too, were released several hours later.
"There is a concerted campaign to intimidate international journalists in Cairo and interfere with their reporting," said U.S. State Department spokesman P.J. Crowley, commenting on the situation in a post on the Twitter social networking site Thursday afternoon.