WASHINGTON — Firearms sales and federal background checks for purchases soared to all-time highs in March as the coronavirus pandemic brought buyers out in record numbers, even though gun dealers were included in orders shutting down businesses in some states.

The FBI conducted 3.7 million background checks last month, according to its latest figures, the highest total since the national instant check system for buyers was launched in 1998 and 1.1 million higher than the number conducted in March 2019.

The period of March 17-21 was an especially busy period for the background check system. More than 210,000 checks were conducted on March 21 alone, the record for a single day.

The March figure also topped the previous high of 3.3 million set in December 2015, after the Obama administration raised the prospect of restricting assault weapons after the deadly mass shooting in San Bernardino, California.