Murders of police officers rose by nearly 60% during 2021, amid a wider rise in violent crime across the US, according to FBI Director Christopher Wray.
In an interview with 60 Minutes, Mr Wray said 73 officers were killed in the line of duty last year.
Murders of all kinds across the US have risen dramatically since 2019.
Mr Wray said violence against police was a "phenomena" that "doesn't get enough attention".
He said it amounted to an officer killed every five days. Around 1,000 people are killed in the US by police each year, although only a small proportion of cases lead to criminal charges.
Mr Wray said that "some" of the violence against police is "tied to the violent crime problem as a whole".
But, he said, authorities believe that "an alarming percentage" of the officers killed were targeted and "killed through things like being ambushed or shot while out on patrol".
"Wearing the badge shouldn't make you a target," he added.
Mr Wray did not disclose how many of the 73 officers were targeted in such a manner.
In January, however, the Fraternal Order of Police (FOP) said that it had recorded 103 "ambush-style attacks" on officers in 2021, resulting in 130 officers shot and 30 killed.
In 2020, the FBI's own data estimates that murders rose 29% from 2019, the sharpest increase since national-level record keeping began in 1960.
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