NEW YORK (AP) — Phone companies will have greater authority to block questionable calls from reaching customers as regulators adopted new rules to combat automated messages known as robocalls.

Rules adopted Thursday by the Federal Communications Commission represent the latest tools against "robocalls," which pester consumers, sometimes multiple times each day, and often push scams.

Phone companies can already block some calls that trick consumers by showing up on Caller ID with fake numbers. The new rules make clear that they can block additional calls that are likely scams, such as numbers that start with a 911 area code, or one that isn't currently assigned to anyone.

The changes won't stop robocalls completely, though experts say these steps are a good start.