Protesters have descended on the home of Stephen Miller, a top adviser to Donald Trump, to express their frustration with the administration's “zero tolerance” immigration policy.

Carrying mock "Wanted" posters bearing Mr Miller’s face, and chanting slogans like "Say it loud, say it clear: immigrants are welcome here," some 20 protesters marched to the 32-year-old’s apartment in Washington, DC, on Monday, according to local reports.

The participants were protesting the Trump administration’s new policy of referring anyone caught crossing the border illegally for prosecution.

The so-called “zero tolerance" policy – of which Mr Miller was reportedly a key architect – resulted in the separation of more than 2,000 migrant children from their parents before the US president put an end to the practice last week.

Hundreds of children have yet to be reunited with their parents, and it is unclear whether the government has a system in place to do so.

"As long as Stephen Miller and the Trump regime terrorise black and brown communities, penalize immigrants and ban Muslims, they will be met with frequent displays of public anger and moral outrage," Jesse Rabinowitz, an organisers of Monday’s protest, told USA Today.

Mr Miller was not home at the time of the protests, as he was accompanying Mr Trump to a rally in South Carolina.

‘Families belong together’ protests over Trump immigration policy Show all 8 1 /8 ‘Families belong together’ protests over Trump immigration policy ‘Families belong together’ protests over Trump immigration policy Mishawaka, Indiana AP ‘Families belong together’ protests over Trump immigration policy Washington DC AFP/Getty Images ‘Families belong together’ protests over Trump immigration policy New York Mayor Bill De Blasio speaks in Tornillo, Texas alongside the many other US mayors who have called for detained immigrant children to be reunited with their families AP ‘Families belong together’ protests over Trump immigration policy Albuquerque Mayor Tim Kelle leaves a teddy bear as a gift for detained immigrant children in Tornillo, Texas AP ‘Families belong together’ protests over Trump immigration policy Seattle Mayor Jenny Durkan and Los Angeles Mayor Eric Garcetti leave sandals as gifts for detained immigrant children in Tornillo, Texas AP ‘Families belong together’ protests over Trump immigration policy San Diego, California EPA ‘Families belong together’ protests over Trump immigration policy US embassy, Mexico City AFP/Getty Images ‘Families belong together’ protests over Trump immigration policy San Diego, California EPA

Mr Miller pushed the president to implement the zero tolerance policy this spring, and advocated for the separation of migrant children from their families as a deterrent to illegal immigration, according to the New York Times.

He has yet to express any reservations about the separation of immigrant families, despite Mr Trump doing so repeatedly.

The policy adviser was previously targeted after digital news outlet Splinter published his telephone number online. The leak resulted in dozens of texts to Mr Miller, criticising him for his role in the separation of immigrant families.

Other supporters of the zero tolerance policy, such as the secretary of homeland security, Kirstjen Nielsen, have also been the target of protests in recent weeks.

Ms Nielsen was shouted out of a DC-area Mexican restaurant by protesters chanting “Shame!”