FBI: US disrupted July 4 attack plots

The United States disrupted an undisclosed number of plots to kill Americans on or around the Independence Day holiday, and arrested suspects with alleged links to the Islamic State group, the FBI said.

A spokesman, citing FBI director James Comey, said that there had been "more than 10 arrests in the past four to six weeks" of people believed to have ties to the extremist group.

"Some" of these arrests were connected to possible attacks on the Fourth of July celebrations in the United States, said FBI spokesman Paul Bresson.

The United States was on heightened alert during the long Fourth of July holiday weekend, ramping up security across the country and urging people to stay alert over fears of a terrorist threat.

The Federal Bureau of Investigation, Department of Homeland Security and National Counterterrorism Center had all warned of an increased risk of attacks.

New York and other major cities, including the capital Washington, were on guard, although the weekend passed off peacefully.

However, the FBI's disclosure Thursday will renew fears about the terror threat facing the United States, particularly from the Islamic State group.