Republican presidential candidate Herman Cain is now being protected by the US Secret Service, the federal law enforcement agency that protects the president.
Homeland Security secretary Janet Napolitano, in consultations with congressional leaders, authorized Secret Service protection for Cain at the request of his campaign, the agency's spokesman Ed Donovan said on Thursday.
Cain's spokesman said the protection had started but did not respond when asked in an e-mail why the campaign had asked for federal protection as the former pizza company boss tries to become the Republican nominee for president in the November 2012 election.
The Washington Post quoted Cain spokesman JD Gordon as saying the protection was requested after the newspaper's report on Thursday detailing physical skirmishes involving journalists covering the campaign.
Donovan said it was not unprecedented for candidates to get protection in the months before the start of an election year.
Cain is the first Republican in the 2012 presidential race to receive Secret Service protection.
Barack Obama, elected president in November 2008, got Secret Service protection in May 2007, the earliest ever for any candidate.
New York Senator Hillary Clinton, now Obama's secretary of state, was under Secret Service protection before she entered the 2008 presidential race because of her status as the wife of former President Bill Clinton.