A Delaware man photographed carrying a Confederate battle flag during a deadly riot in the US Capitol has been arrested.

Federal prosecutors said Kevin Seefried was arrested in Delaware along with his son Hunter Seefried.

Prosecutors said both men entered the Senate building through a broken window.

They were charged with unlawfully entering a restricted building, violent entry and disorderly conduct on Capitol grounds and degradation of government property.

Court documents say the men were identified after the FBI was told by a co-worker of Hunter Seefried’s that he had bragged about being in the Capitol with his father.

The pair were part of a larger group that verbally confronted members of the Capitol police over a 15-minute period and were spotted on surveillance video, according to the documents written by an FBI special agent.

The FBI agent wrote that authorities compared Kevin Seefried’s driver’s licence photo to images of him carrying the flag during the riot to confirm his identity.

They both spoke voluntarily to the FBI on Tuesday and admitted they had been present at the riot, according to court documents.

“Kevin Seefried also explained that he brought the Confederate Battle flag seen in Exhibit A to the District of Columbia from his home in Delaware where it is usually displayed outside,” the agent wrote.

Earlier, a retired Pennsylvania firefighter was arrested on suspicion of throwing a fire extinguisher that hit three police officers during the siege.

Former Chester firefighter Robert Sanford was arrested on charges including assault of a police officer and unlawfully entering the Capitol.

The charges against Sanford are not related to the widely publicised attack on an officer who was hit with a fire extinguisher and died.

Sanford is appearing in federal court in Pennsylvania but the case will be prosecuted in Washington.

President Donald Trump’s supporters stormed the US Capitol building last week after a rally the president held to repeat baseless election grievances.

Five people died during the siege, including a Capitol police officer, a woman shot by police and three people who had medical emergencies.