The suspect in a Molotov cocktail attack on a Jewish protest march in Colorado has appeared in court facing more than 100 charges over an incident that injured 15 people.

Mohamed Sabry Soliman is alleged to have thrown firebombs and sprayed burning petrol at a group of people who had gathered on Monday in support of Israeli hostages held by Hamas.

Prosecutors now say 15 people – eight women and seven men – were hurt in the attack in the city of Boulder. Three are still in hospital.

The oldest victim was 88 years old.

Soliman, a 45-year-old Egyptian who federal authorities said was in the country illegally after overstaying a tourist visa, faces 28 attempted murder charges, as well as a host of other counts relating to his alleged use of violence.

He also faces a count of animal cruelty for a dog that was hurt, bringing to 118 the total number of criminal counts.

Boulder County District Attorney Michael Dougherty told reporters that he could face a centuries-long prison term if convicted.

“The defendant is charged with attempted murder in the first degree as to 14 different victims,” he said.

“If the defendant is convicted and those sentences run consecutively, that would be 48 years in state prison for each of the 14 victims, which comes to 672 years.”

Soliman is also expected to be charged with federal hate crime offences.

Soliman’s immigration status has been at the centre of President Donald Trump’s administration’s response to the attack.

This week his wife and five children were detained by immigration agents as the White House took to social media to taunt them about an impending deportation.

“Six One-Way Tickets for Mohamed’s Wife and Five Kids,” the official account posted on X.

“Final Boarding Call Coming Soon.”

But on Thursday a judge imposed a temporary restraining order that bars any attempt to remove them from the country.

Police who rushed to the scene of Monday’s attack found 16 unused Molotov cocktails and a backpack weed sprayer containing petrol that investigators say Soliman had intended to use as a makeshift flamethrower.

In bystander videos, the attacker can be heard screaming “End Zionists!” and “Killers!”

Monday’s incident came less than two weeks after the fatal shooting of two Israeli embassy staffers outside a Jewish museum in Washington, where a 31-year-old suspect, who shouted “Free Palestine”, was arrested.

- Agence France-Presse