U.S oil and gas company Apache Corp. said Wednesday it is moving an undisclosed number of workers out of Egypt due to civil unrest in that country.

Apache's production, located in remote locations in the Western Desert, has continued uninterrupted, the company said in a statement on its website.

Operations in Egypt accounted for about 20 percent of the Houston company's oil and natural gas output in the third quarter.

Bill Mintz, a spokesman for the company, declined to say how many workers have been taken out of Egypt.

Violence escalated in Cairo. Supporters of President Hosni Mubarak attacked protesters with fists, stones and clubs as the Egyptian government rejected international calls for the leader to end his 30-year rule immediately. Mubarak has said he will step down at the end of his term in September.

Shares of Apache rose 2 percent to $121.24 on the New York Stock Exchange.