A solid majority of U.S. teachers go to work each day anxious that a shooting will unfold at their school, a trend that has paralleled the rising number of such incidents across the U.S., a report released on Friday showed.

A Pew Research Center survey of about 2,500 teachers showed that more than half of them were at least somewhat concerned and another 18% were extremely or very worried about the possibility of a shooting at their school.

Gun control and school safety have become major political and social issues in the U.S. where the number of school shootings has jumped in recent years.

There were 912 school shootings between 2021 and 2023, more than three times as many as any other three year-period in four decades of data collection, according to the K-12 School Shooting Database website.

The survey, conducted from Oct. 17 to Nov. 14, 2023, indicated that 31% of teachers in urban schools had a gun-related lockdown during the 2022-23 school year, 10 percentage points higher than teachers in both suburban and rural schools.

Only three out of 10 teachers indicated that their school had done an excellent or very good job preparing them for an active shooter, the survey showed.

More than three-fifths of teachers surveyed said improved mental health screening and treatment for children and adults would be extremely or very effective at preventing shootings. Half said police officers or armed security in schools would be highly effective.

More than a quarter of teachers who lean Republican and only 3% of who lean Democrat thought allowing teachers and school staff to carry weapons would be highly effective in stopping school shootings.