An armed Trump supporter sparked a security alert at an immigrant community centre in El Paso when he was spotted “brandishing” a knife outside.

Thomas Bartram, 21, was detained by police following reports of a suspicious man parked in front of the building, four days after 22 people were killed in a mass shooting in the city.

Related Video: Police: El Paso Walmart Shooting Suspect Targeted Mexicans

Mr Bartram, who was legally carrying a gun, was questioned by officers but was released after they decided he had not committed any criminal offence.

Photographs and video footage posted online showed Mr Bartram being arrested next to a truck bearing a mocked up image of the US president as Rambo wielding a rocket launcher.

Staff at the Casa Carmelita criticised the decision by the El Paso police department, claiming that the man had “clear intent to conduct an armed assault” on the day of Mr Trump’s visit.

“He was sitting in his truck wearing blue latex gloves, and brandishing a knife,” they posted on the organisation’s Facebook page.

“Police recovered a loaded gun, ammo, and a bag of white powder from his person. This happens just as Trump departs El Paso and follows a pattern of local organisers being targeted and increased violence and hate crimes.”

Organisers also claimed the Trump supporter's presence outside the centre caused women to start “fleeing down the street, warning neighbours as they ran away.”

The El Paso police department tweeted that “officers responded to a suspicious subject at the 900 block of Stanton near Casa Carmelita” at 7pm on 7 July.

“The subject was detained, interviewed and released after it was determined that no criminal offence had been committed,” it added.

A police spokesman confirmed the detained man was carrying a firearm legally.

Mr Bartram had previously been photographed wearing plastic safety goggles while visiting a vigil for the victims of the shooting in El Paso.

He claimed he drove to the city from Houston to “come out and support” Mr Trump and denied allegations he was brandishing the weapons.

Story continues

Asked about the knife and the gloves, he told NBC News: “I was eating prickly pears.” The “white powder” was a protein supplement, he said.

Mr Bartram added: “I’m definitely not a white supremacist.”

Seven of the victims of the El Paso shooting carried out by a suspected white supremacist were Mexican citizens. Thirteen were US citizens, one was German and one remains unknown.