The National Rifle Association's annual convention last weekend cost Dallas police $575,000, the city manager said on Thursday.

The NRA spent $150,000 on 400 off-duty officers who patrolled the Kay Bailey Hutchison Convention Center and its perimeter starting last Thursday through Sunday.

Dallas' $575,000 bill includes security and traffic control for rallies, protests and President Donald Trump and Vice President Mike Pence's visit to Dallas to speak at the convention, City Manager T.C. Broadnax said.

The money came out of the city's nearly $1.3 billion general fund, which also pays for day-to-day services such as public safety and public works.

Dallas police said they didn't give out overtime for officers who worked during the convention because they were still on duty. It's unclear whether police had to take resources out of the already strapped patrol division to secure events related to the convention.

Outside police agencies also volunteered to help with security, Dallas police said.

Dallas gave the NRA roughly $400,000 in free rent, which came out of fees that are collected from guests staying at large Dallas hotels, to lure its convention to town.

The city's convention and visitors' bureau estimated that the convention would bring in $24 million in direct spending but didn't say how much of that would be for hotel rooms.

Staff writer Robert Wilonsky contributed to this report.