(CBS) Worried that war in Iraq could lead to terrorist reprisals at home, the Department of Homeland Security has raised the terror alert one level to orange, or "high," and called for an increase in security measures nationwide.

"The FBI, the Department of Justice and the Department of Homeland Security are working closely to identify and stop those who would facilitate terrorist activity through fund-raising, logistical support and recruitment," Homeland Security director Tom Ridge told a news conference Tuesday morning.

Calling the effort "Operation Liberty Shield," the department deployed extra Border Patrol officers, stepped up patrols at seaports, airports and nuclear power plants and safeguards over the nation's food supply, officials said.

Other steps include more security surrounding rail travel and shipments, increased Coast Guard patrols near key petroleum and chemical facilities, and more security at facilities handling radioactive materials. The Department of the Treasury will keep a closer watch on financial networks and payment systems, and several government agencies will be more vigilant on health and food safety issues.

The fear was given some credence Tuesday when Saddam Hussein's oldest son Udai warned Americans "they should not think there's a safe place inside, or outside, Iraq," reports CBS News Correspondent Lara Logan.

There is a dramatic increase in security around the White House, reports CBS News Correspondent Peter Maer. Metal barricades now ring the area within two blocks of the building. Uniformed Secret Service officers are posted at checkpoints, with gas masks part of their gear, and there is also a marked increase in police vehicles parked near the White House.

"We have taken these actions because intelligence reporting indicates that while al Qaeda and those sympathetic to their cause are still a principal threat...Iraqi state agents, Iraqi surrogate groups, other regional extremist organizations or ad hoc groups or disgruntled individuals may use this time period to conduct terrorist attacks against the United States, either here or abroad," said Ridge.

Several officials said the security increase was not related to a specific body of intelligence, but a general belief that terrorists may try to respond to the U.S.-led war on Iraq by striking at American interests, either at home or overseas.

CBS News Correspondent Bob Orr reports that, during the first Gulf War, terror attacks around the globe increased threefold. All of those were overseas, but analysts say this time, the threat could come home.

"Ever since Sept. 11, the United States has raised its guard to protect its homeland. But in the context of international conflict we should be prepared that there may be sleeper cells that will take strikes at us here in the United States," says John Parachini, a terrorism analyst.

The department also called on governors to deploy National Guard troops or extra state police to protect key public facilities.

"The increase in the threat level is a signal to law enforcement, government officials at all levels and representatives of the private sector to implement specific protective measures," said Ridge.

Orange, second highest on the five level, color-coded terror alert system, means intelligence and analysis suggests that a high risk of terrorist attacks inside the United States exists. Yellow, a step below, means an "elevated" level of risk. It has been about 2½ weeks since the last orange alert ended and reverted to yellow.

The heightened alert took effect immediately after President Bush declared in a nationally televised address that Iraqi leader Saddam Hussein must leave Iraq within 48 hours or military action would be mounted to oust him.

The move marked the third time the administration has raised the terror alert status since the system was put in place about a year ago.

The FBI sought to assure Muslims and Arab-Americans it will respond quickly to any reports of hate crimes, although some Muslims and Arabs fear war might result in harassment or deportation.

"All of us are going to be suspects," said Sarah Eltantawi, spokeswoman for the Muslim Public Affairs Council. "There is just this profound sense of disappointment about what America is becoming."

Ridge said those seeking asylum in the U.S. would be given extra scrutiny now.

"We just want to make sure that those who are seeking asylum, number one, are who they say they are and, two, are legitimately seeking refuge in our country because of political repression at home, not because they choose to cause us harm or bring destruction to our shores," he said.

Ridge defended detaining those seeking asylum who come from countries with known or suspected ties to al Qaeda.

"We want to make absolutely certain during this period of time you are who you say you are and you're coming to this country that invites people from around the world, that has been open and welcoming to people around the world," he told reporters.