Island police are issuing warnings as a new state law takes effect that strictly prohibits the use of hand-held cell phones while driving.

Effective March 31, the warnings will become hefty fines, police said Monday.

Signed by Gov. Charlie Baker in November, the so-called Hands Free law banning the use of hand-held phones while operating a vehicle took effect Sunday. The new law expands and strengthens a 2010 state law that prohibits texting while driving.

“The previous law wasn’t crafted particularly well,” said Edgartown police chief Bruce McNamee. “It was difficult for us to enforce; this one may have removed some of the loopholes.”

Under the new law, drivers are allowed to talk on their cell phones only when using a speaker phone, bluetooth or other hands-free technology. Phones can be used for navigation, but must be mounted on a dashboard or windshield. Emergency calling is allowed.

Drivers under the age of 18 are already prohibited in Massachusetts from any use of cell phones while behind the wheel.

Island police contacted Monday said they have not necessarily stepped up enforcement, but are on the lookout for drivers who may need education about the new law.

“We’re not working any more or less, we’re not gearing towards any sort of special enforcement,” said Tisbury police chief Mark Saloio. “Currently, we’re just gearing towards more awareness.”

Since Sunday Tisbury police have issued nine warnings to distracted drivers, Chief Saloio said. Edgartown has issued two warnings, while Oak Bluffs, Chilmark and Aquinnah reported they had issued none.

“I imagine we’ll be doing a lot of verbal warnings,” said Oak Bluffs Sgt. Michael Marchand. “This time of year we have mostly Islanders here. So it goes a long way in giving those warnings out.”

Beginning March 31, the enforcement part of the law kicks in with hefty fines: $100 for the first offense, $250 for the second offense plus a mandatory distracted driver education course, and $500 for a third offense, with insurance penalties attached.

Police said the goal of the law is indisputably to save lives.

“Every traffic regulation is written in blood,” said Chief Saloio, reprising a phrase he said was used by his former chief. “Think about what accumulated over the years that led to this law . . . At the end of the day, enough people were injured or killed that the legislature took action.”

He added: “We hope it works.”

Read full text of Hands Free Law.

Aaron Wilson contributed reporting.