A former firefighter has been arrested after he was caught on video throwing a fire extinguisher that hit three police officers during the Capitol riots. 

Robert Sanford, 55, from Pennsylvania, recently retired from the Chester Fire Department, was arrested on charges that include assault of a police officer, disorderly conduct on Capitol grounds, civil disorder and unlawfully entering the Capitol.

He will appear in a virtual hearing in federal court in Allentown, Pennsylvania on Thursday, Reuters reported.

His arrest is not connected to the death of Officer Brian Sicknick, who also was attacked with a fire extinguisher during the storming of the Capitol. 

The charging documents say: "The object appears to strike one officer, who was wearing a helmet, in the head. The object then ricochets and strikes another officer, who was not wearing a helmet, in the head. The object then ricochets a third time and strikes a third officer, wearing a helmet, in the head.” 

One of the officers was taken to hospital but later cleared for duty. 

Mr Sanford took a bus to the Capitol and told a friend when he returned home that he had been on the grounds for 10 minutes before leaving but did not mention throwing anything at officers, authorities said.

The Justice Department has brought over 70 criminal cases since the riot. Many arrests have been made because of the large number of social media posts from the storming of the Capitol. The FBI is going through over 100,000 images and videos, Reuters reported.

Most of the rioters were allowed to leave DC, leading to authorities arresting insurrectionists all over the country. 

The Associated Press contributed to this report.