Baltimore Police Commissioner Michael Harrison appeared before a city council committee Thursday and addressed a rise in carjackings throughout the city, WBAL-TV 11's Tre Ward reports.

Harrison said Thursday there has been a nearly 30% increase in carjackings since this time last year. Police report that many of the carjackings were committed by juveniles.

"They're using these cars to commit other crimes, shootings and other armed robberies and sometimes just to joyride," Harrison told the committee.

As of Sept. 28, police have investigated over 400 carjackings and arrested more than 700 suspects, according to the Baltimore Police Department.

"We've made a number of arrests. We continue to make arrests. We continue to pursue them, work to find link analysis to tie them to not just the one armed robbery, but to all the crimes they're committing," Harrison said. "But we always need community help, so when people know information, please help us with information and provide it to us, so we could help stop them from committing these bad acts."

As the department works to combat this increase in crime, Harrison had a message for the criminals.

"If violent crime is the life you choose, we're going to make certain prison is the price you pay," Harrison said before the committee.

Police did not say as to why there has been a sharp increase in carjackings. Though Baltimore Police Lt. Col. John Herzog told the Baltimore Sun, it may because it's a crime of opportunity as all the suspect needs is one person who is not paying attention. Herzog went on to say it is easier to steal a car that is running than when it's locked due to anti-theft technology, the Sun reports.

Ward reports police offered some tips for drivers to remain safe. Police said to be sure to lock your doors, always be aware of your surroundings and leave space between vehicles.