Republican presidential aspirants Donald Trump and Ben Carson will soon receive protection from the Secret Service due to increasing threats to their lives.

The Secret Service became increasingly concerned about Carson's life after he received "off the charts" death threats following his recent comments against Muslims becoming president of the United States, NewsMax reported, citing an anonymous Washington source privy to the agency's plans.

The source reportedly said that there is evidence to believe that home-grown terrorists linked to the Islamic State jihadist group are targeting both Carson and Trump.

"It is widely believed ISIS would like to strike a major political target in the US. The Federal Bureau of Investigation has not offered such an assessment publicly," the unnamed source was quoted by NewsMax as saying.

Carson's campaign team supposedly initially refused protection from the Secret Service, but eventually gave in after the agency warned of grave danger to his life.

Armstrong Williams, Carson's business manager, refused to confirm or deny the protection supposedly to be given on the retired neurosurgeon as early as next week.

"We don't comment on security matters involving Dr. Carson," Williams said.

Trump, meanwhile, supposedly officially asked for protection from the Secret Service, primarily due to "by far the biggest crowds" he had drawn in the past weeks. The controversial business tycoon is currently the front-runner in various Republican surveys.

It has also been previously reported that Trump is being targeted by Mexican drug lord Joaquin "El Chapo" Guzman because of the Republican candidate's statements against immigrants.

Democratic presidential front-runner Hillary Clinton will also receive extra protection from the Secret Service, according to the source.

Clinton has received security from the Secret Service since 2001, when she left the White House as first lady, but she will reportedly be given upgraded security as the elections draw near.