Updated

British officials say terrorism-related arrests have risen to a record high level as the threat to the country has increased.

The Home Office said Thursday there were 379 arrests for terror-related offenses in the 12-month period ending June 2017. That represents a 68 percent increase over the year before. It is the highest numbers of arrests since the government started keeping tallies in 2001.

The figures reflect a surge in arrests as police made wide-ranging sweeps after deadly attacks in London and Manchester earlier this year.

Security Minister Ben Wallace said the figures show police and security services responding to "an unprecedented period of terrorist activity in the U.K."

The figures show roughly half of the people arrested were released without being charged.