The deadly assault on a luxury Nairobi mall Saturday has sent shock waves around the world, raising concerns about security at shopping centers amid fears of copycat violence or other terror attacks, according to industry officials and other experts.
As Kenyan forces struggled Monday to take control of the Westgate mall on the third day of the horrifying attack, U.S. shopping center firms are considering ramping up security measures at thousands of malls across the country, industry sources said.
"There's going to be a response," said Malachy Kavanagh, a spokesman for the International Council of Shopping Centers, a U.S.-based trade group of mall and shopping-center owners.
He added that the U.S. Department of Homeland Security is likely to coordinate with corporate security chiefs and law enforcement agencies following the attack in Nairobi, which left at least 62 people dead, according to the Kenyan Red Cross.
(Read more: Kenya police retake mall, all hostages believed free)
Officials may also increase the police presence at many shopping complexes by enlisting off-duty officers to stand guard and defend against incursions, Kavanagh said. He added that mall proprietors will be careful to take their cues from consumers, who may already be weary from boosted security at airports.
For mall owners and security specialists, the carnage in Kenya is just the latest evidence of shopping centers' vulnerability to terror attacks.
"Since 9/11, the industry has taken a very different view of terror, and the potential for it," Kavanagh said, adding that the industry has spent millions on security training initiatives at the more than 1,500 enclosed malls in the U.S. since the Sept. 11, 2001, attacks on New York City's World Trade Center and the Pentagon in Washington, D.C.
"The big fear" for many mall proprietors is the possibility of a "copycat attack" in the wake of the siege of the Westgate Shopping Mall by militants from Al Shabaab, a Somali terrorist organization linked to al Qaeda. The group has said the assault was retribution for a 2011 push by Kenya into Somalia.
In an interview with NBC News on Monday, New York City Police Commissioner Ray Kelly said a mall is what security experts call a "soft target" because "you have no external checks to security."
"You need to have access to a mall and as a result, security—or some security you see in public buildings or public sector buildings—is not possible," Kelly said.