VALLEJO -- A homeless man known as "Nomar" living in downtown San Francisco has been identified by Vallejo authorities as the source of hundreds of 911 calls that have tied up the city's emergency call system.

Vallejo police Lt. Richard Nichelman said authorities determined the male caller's location after learning that the phone he calls from can only dial 911. The phone was shipped to San Francisco by the company in Oklahoma that makes these phones, made specifically for homeless people to use in emergencies.

Although Vallejo police attempted to slow the flow of calls from the man, who often calls himself "Nomar," but goes by several other aliases, after publicizing the story, calls have continued.

"Nomar" called about 30 times on Monday.

"He is a real thorn in our side," Nichelman said.

Calls began coming into the Vallejo emergency dispatcher in June, Vallejo police communications manager Jim Powell said, and the reported emergencies have ranged from suicide attempts to armed robberies.

The caller usually calls between two and 30 times each day, but sometimes take a few days off, according to Powell. Emergency calls are routed through the California Highway Patrol, which does not send recognized "Nomar" calls to Vallejo police, so the actual volume of calls received from the caller is even higher than the Vallejo police estimate of 300.

Although police have begun to recognize the incident descriptions the caller gives and the sound of his voice, Powell said police would have to be sure that it is the prank caller in order to ignore an emergency calls.

That is not always possible, Powell said, so police are stuck responding to the fake emergencies.

The resources used to respond to the fake emergencies put the rest of the public at danger, Nichelman said.

Vallejo police have never received prank calls to this extent, although the occasional child's prank call comes in, according to Powell.

As to charges "Nomar" may face if caught, Powell said the decision is up to the district attorney. However, he said his department would recommend one count of filing a false emergency claim and one count of misusing 911 for every call "Nomar" makes.

"We will continue to look for him either until we find him or until he stops calling for a significant amount of time," Powell said.