New Orleans ? Nine months after they rode to the rescue in the desperate aftermath of Hurricane Katrina, National Guardsmen carrying M-16s returned to the city Tuesday to reinforce a depleted police department and battle a surge in violence.

The 100 or so soldiers will patrol the streets in ravaged neighborhoods left deserted by Katrina, freeing up police officers to concentrate on more heavily populated sections.

“We’re just trying to give a hand to the city of New Orleans,” said Lt. Melvin Edwards, 32, a member of 239th Military Police Company.

Gov. Kathleen Blanco sent in the National Guard at the mayor’s request after a bloody weekend in which six people were killed.

“Criminals, hear me loud, hear me clearly: There is law and order in New Orleans,” she said. “We will not let the criminals take root as our families return.”

The troops, dressed in full camouflage fatigues, carried M-16s, handguns and belt clips of ammunition as they arrived in a convoy of 75 vehicles. They parked their Humvees and tanker trucks in formation in front of the Convention Center, drawing waves and thumbs-up from onlookers.

With the Mississippi River bridge behind them, members of the Louisiana National Guard march in New Orleans. A convoy of 100 armed National Guard military police troops rolled into the city Tuesday to patrol the streets following a surge in violent crime.

Up to 200 more Guardsmen will be sent in later, bringing the total in the city to 300. In addition, 60 state police officers were sent to help keep the peace.

As the soldiers arrived, New Orleans police were investigating another slaying, that of a 22-year-old man. The killing brought this year’s murder toll to 54.

The bloodshed has raised fears that violence is back on the rise in a city that was plagued by crime before Katrina drove out half its population of 465,000.

Community leaders are afraid the violence will discourage people from returning.

King Milling, a New Orleans banker, said he was “just delighted” by the troops’ arrival. “The powers-that-be recognize that this is an issue that we must deal with,” he said.