The Justice Department said Friday teams of federal agents are being dispatched to four additional cities to combat violent crime: Mesa, Ariz.; Orlando, Fla.; San Bernardino, Calif.; and San Juan, Puerto Rico.

The announcement comes as the FBI prepares to release new numbers next week showing that violent crime continues to rise nationally.

At the same time, a new internal report rapped task forces for failing to coordinate efforts — and potentially endangering agents' lives.

Attorney General Alberto Gonzales was to announce the additional task forces during a Friday afternoon speech at the Washington headquarters of the Bureau of Alcohol, Tobacco, Firearms and Explosives.

The ATF's Violent Crime Impact Teams will be deployed to each of the four cites, bringing the total number of regions where they have been deployed to 29, a Justice official said.

Additionally, an FBI Safe Streets Task Force, which focuses on gang activity and other violent crimes, is being sent to Orlando. The FBI has dispatched more than 180 teams nationwide.

Orlando is getting both FBI and ATF help because of its sprawling metropolitan region, said the official, who spoke on condition of anonymity because the announcement had not yet been made.

No additional funds are expected to be funneled to the communities to bolster their own law enforcement efforts, the Justice official said.

Meanwhile, a report by Justice Department Inspector General Glenn A. Fine found that federal crime-fighting task forces often duplicate efforts and compete for help from local authorities. Moreover, the report concluded, the teams do a poor job of communicating, resulting in at least three cases of federal agents mistaking each other for criminals.

Those so-called "blue-on-blue" cases, occurring in the audit of eight cities, could have endangered the lives of the agents. They included:

_An undercover ATF agent and informant in Chicago bought a loaded gun from an informant working for the FBI's Safe Streets task force.

_FBI Safe Streets agents in Atlanta pulled over a member of a U.S. Marshals Service fugitive task force whose car matched the description of a suspect that both teams were looking for.

_ATF agents working an undercover sting at a Las Vegas gun show arrested a suspect for illegally buying firearms. The buyer turned out to be an informant working for the FBI — even though the ATF had taken steps to make sure there would be no overlap between federal agencies.

The report concluded that "more consistent efforts" are needed by the task forces, particularly FBI teams, to afford police a greater measure of protection.

Fine's inspectors studied task forces in eight cities: Atlanta, Birmingham, Ala., Camden, N.J., Chicago, Gary, Ind., Las Vegas, Los Angeles, and Philadelphia. Nearly 130 task force members in the cities reported working on at least 45 duplicate investigations.

Nationally, 210 task forces among four Justice Department agencies were working in 256 cities during a three-year period from 2003 to 2006.

Justice spokesman Dean Boyd said the agencies were ordered in March to make sure their task forces coordinate and share information with each other to prevent overlap. Additionally, Deputy Attorney General Paul McNulty last month told all 93 U.S. attorneys to meet with task force leaders in their districts to fix any coordination problems.

"These steps will serve to enhance the efficacy of our violent crime reduction efforts and will ensure that the department's violent crime task forces work together to make our communities safer," Boyd said.

New FBI data, set for release Monday, will show an increase in violent crime for the second straight year, officials have said. The 2006 rise is expected to be modest, however, according to three Justice officials speaking on condition of anonymity because the data have not been released publicly.

Violent crime rose by 2.2 percent in 2005 — the first increase since 2001.