The US Department of Justice has arrested a man who allegedly planned an attack on Election Day in the name of the Islamic State group.

The suspect, Nasir Ahmad Tawhedi, 27, is a citizen of Afghanistan residing in Oklahoma City, Oklahoma, according to prosecutors.

“This defendant, motivated by ISIS, allegedly conspired to commit a violent attack, on Election Day, here on our homeland,” said FBI Director Christopher Wray in a statement on Tuesday.

The FBI said he was attempting stockpile firearms, and had taken steps to liquidate his family’s assets and relocate members overseas.

Mr Tawhedi is charged with providing, attempting to provide, and conspiracy to provide support or resources to a foreign terrorist organization; and with trying to procure firearms and ammunition to use to commit a felony or act of terrorism.

The FBI said Mr Tawhedi worked with an unnamed co-conspirator, who is a juvenile relative and also a citizen of Afghanistan. It accuses him of consuming Islamic State propaganda via the internet, based on Google records obtained by law enforcement, and donating to a charity used as a front for IS.

“We will continue to combat the ongoing threat that ISIS and its supporters pose to America’s national security, and we will identify, investigate, and prosecute the individuals who seek to terrorize the American people,’’ said Attorney General Merrick Garland.

According to the BBC news partner CBS, federal investigators’ affidavit alleges that Mr Tawhedi searched for surveillance cameras in Washington, and webcams showing the White House and Washington Monument. It also alleges that he researched states with more lax gun laws.

Mr Tawhedi sought AK-47 assault rifles to use in the attack, authorities claim. On 7 October, he and the co-conspirator met with individuals who actually worked undercover for the FBI to purchase the weapons and ammunition.

After the purchase, Mr Tawhedi and his co-conspirator were arrested.

In an interview conducted after his arrest on Monday, the FBI said Mr Tawhedi allegedly confirmed he planned an Election Day attack that would target “large gatherings of people” and that he planned to die carrying it out.

Mr Tawhedi arrived in the US in September 2021 on a special immigrant visa with his wife and young child. He lived in Oklahoma City at the time of his arrest.

It is not immediately clear if he has legal representation.