Indiana Gov. Mitch Daniels signed a law Monday giving prosecutors more tools to battle human sex trafficking ahead of this weekend's Super Bowl.

Daniels and other state leaders have said they were concerned sex traffickers would target the estimated 150,000 football fans flocking to Indianapolis for Sunday's football championship. They cited increased levels of prostitution that have accompanied many major sports events around the country.

"This puts up the 'Don't Try It Here' sign in Indiana," Daniels said before signing the measure into law.

Prosecutors and other supporters say the bill would make it easier to prosecute sex trafficking cases involving victims younger than 16 and broaden the law for cases with older victims. The bill makes recruiting, transporting or harboring anyone younger than 16 for prostitution a felony punishable by 20 years to 50 years in prison.

The measure won unanimous support in the House and Senate and was the first bill signed by Daniels this year.

"Today we close loopholes in Indiana law so our police and prosecutors have the legal tools they need to crack down on those who traffic young victims in a growing area of criminal enterprise that is considered a modern form of human slavery," Attorney General Greg Zoeller said in a statement.

Indiana State Police Superintendent Paul Whitesell said there are 30 state troopers already working on the problem in the city, although he said he did not want to disclose their tactics or the state's strategy.

"There is a significant number of law enforcement looking for these people," Whitesell said.