A man arrested in a Chicago suburb had shared a ⁠document expressing white supremacist views and outlined an alleged plan to carry out a mass shooting, potentially targeting a Hindu place of worship, police ⁠said on Wednesday.

Alexandros Paporakis, 19, was ​arrested on Sunday after an individual reported receiving concerning electronic communications from him, Palatine police said. It was not immediately clear if he had ⁠legal representation.

Detectives had executed a search warrant at Paporakis’ residence and recovered a rifle, multiple loaded rifle magazines and hundreds of rounds of additional rifle ammunition, police said.

“Among ⁠the recovered items was a tactical vest containing body armor and a patch displaying imagery associated ​with white supremacist extremism,” Palatine police added.

Detectives examined ‌electronic communications and a document attributed ‌to Paporakis – “Why I Fought: A.K.A.: (Aurora Shooter’s Manifesto)” – which had statements expressing white supremacist and extremist ideologies, including ‌references to violence directed toward individuals of South Asian heritage, particularly those of Indian descent.

India’s foreign ministry said it was “deeply concerned” by the incident, and its “anti-Hindu and racist nature” was “particularly disturbing”.

“We expect US authorities to thoroughly investigate the matter, bring those responsible to justice, and take all necessary measures to prevent such incidents,” it said in a statement.

The statement comes days before US secretary ‌of state Marco Rubio’s visit to India, and as long-running efforts to finalize a bilateral trade agreement between the countries have stalled again.

Detectives believe Paporakis may have been ​planning to carry out an attack on 11 October, potentially targeting a Hindu place of worship in Aurora.

“However, the specific intended location has not been confirmed and remains under investigation,” the police said, adding the FBI was assisting in the investigation.

Police said after consultation ⁠with prosecutors from the Cook county state’s attorney’s office, Paporakis faced felony charges of “making ​a terrorist threat” and ​unlawful weapon possession.

The suspect appeared for a ​detention hearing on Wednesday where a judge ordered him detained, according to police, ​who said his next court ‌appearance is scheduled ​for 30 October.

Human ​rights advocates have said that hate against South Asians has spiked in the US in recent years due to factors such as rising anti-immigration rhetoric and policies as well as a rise in white supremacist ideology.