WASHINGTON — The Transportation Security Administration says the nine busiest days in its history occurred this summer as travelers jammed airports.

TSA Acting Deputy Administrator Patricia Cogswell said Thursday that the agency screened 262 million people and 164 million checked bags from just before Memorial Day until the day after Labor Day. That’s up 3.4% from last summer.

Of the nine hectic days, the peak was July 7, when TSA screened nearly 2.8 million airline passengers and crew members.

Cogswell says TSA hired enough screeners, although the agency didn’t give numbers, and worked with airlines to anticipate where screeners would be needed.

TSA has struggled with turnover — about one-fifth of screeners leave every year. The agency has countered with retention bonuses.

It was created in 2001 after the 9/11 terror attacks.