Officer Jeff Innocenti pulls a ticket from his printer during a traffic stop for cellphone use Oct. 3. Montgomery County police are enforcing the state ban on use of hand-held cellphones while driving. (Sarah L. Voisin/The Washington Post)

Drivers who ignore Maryland’s ban on hand-held cellphone use are being chased down and ticketed by Montgomery County police empowered by a change in state law.

Police said they ticketed 202 drivers and issued warnings to 106 more during the first 17 days of October.

Capt. Tom Didone, head of Montgomery’s traffic division, has been deploying officers in unmarked vehicles to look for violators, teaming them with officers in marked chase vehicles. In addition to 308 tickets and warnings for cellphone use, his officers have issued 16 tickets and 19 warnings to people writing, sending or reading text messages.

The crackdown in Montgomery was made possible by an Oct. 1 change in Maryland law that allows police to stop and ticket drivers they see using cellphones. Under an earlier law, they were required to have another reason to pull a driver over before issuing a cellphone citation.

Nationwide, distracted driving was to blame for 3,331 roadway fatalities, 387,000 injuries and 10 percent of all crashes in 2011, according to federal statistics. The percentage gets higher for drivers 19 or younger, with 21 percent who were involved in fatal accidents said to have been distracted by their cellphones.

Rising awareness about the dangers of cellphone and texting distraction has resulted in a wave of police action nationwide. New York state last month created 300 “texting zones” where drivers can pull over along state highways. The zones were created after New York enacted stiffer penalties for distracted driving and spent the summer enforcing them.

New York State Police using unmarked cars issued 16,027 tickets for cellphone use and 5,553 texting tickets between July 4 and Labor Day.

Massachusetts State Police are using tactics like those employed in Montgomery County, deploying teams that include unmarked cars to spot drivers violating the law and marked patrol cars to chase them down. During one three-week period of intensive enforcement, they issued 949 tickets.

In California, Sacramento police say they are focusing attention on highways that have been identified as high-collision zones, looking for drivers using phones or texting.