Raleigh, N.C. — Four months after its introduction, 10-digit dialing continues to cause significant problems for the Raleigh-Wake Emergency Communications Center.

Instead of dialing the 919 area code, more and more callers are mistakenly dialing 911 and hanging up, Raleigh officials said. That prompts a return call from dispatchers, who must verify whether there is an emergency.

If the caller doesn't answer, law enforcement officers are sent to the address listed with the number.

In July, officers were dispatched to check on the welfare of 5,655 hang-up callers – a rate of 7.6 per hour. It's the highest number since problems began with the March 31 conversion to 10-digit dialing, said Emergency Communications Director Barry Furey.

Nearly 3,200 of those dispatches were in the city of Raleigh. While some were cleared before the officer arrived, Raleigh police still spent more than 300 hours last month responding to hang-up calls, Furey said.

Furey stressed that response times to real emergencies are affected when call-takers and dispatchers are occupied with mistake calls.

Anyone who dials 911 by mistake is urged to stay on the line to verify the error.

"If you dial 911 incorrectly, it is imperative that you stay on the line," Furey said. "The only apparent cure is careful dialing. We can't fix this issue without the public's help."

Prior to the area code requirement, the Raleigh-Wake 911 center dispatched officers to about 900 hang-up calls per month. From March to April, that number increased by nearly four times.

In Cary, the number of 911 hang-up calls tripled – from an average of 350 hang-up calls each month from January through March to nearly 1,050 calls in April, town officials said.