Houston ? Eight members of rival New Orleans gangs who had moved to Houston since Hurricane Katrina have been arrested in connection with the slayings of 11 fellow evacuees and other violent crimes, police said Friday.

Investigators, who were still looking for three suspects, said those slain also belonged to the gangs or had some connection to them. Violent crimes attributed to these gangs also have been committed on Houston residents, said police spokesman Alvin Wright.

“They were doing the same thing in New Orleans,” Wright said. “The hurricane brought those rivalries to Houston.”

Although officials emphasized that the vast majority of the 150,000 Katrina victims who have moved to Houston are law-abiding, they say others are partly responsible for a sharp spike in the city’s crime rate in the last few months of 2005. Houston Mayor Bill White asked the Federal Emergency Management Agency last month to pay for a new $6.5 million police task force.

At least 23 evacuees in Houston were either the victim or the suspect in killings between September and December, accounting for nearly 20 percent of the city’s homicides in that span.

Violence has risen not only on the streets but in the schools: Houston’s district, which absorbed about 6,000 student evacuees, increased security this month after at least a dozen major fights involving displaced students. The worst was a near-riot last month in a high school lunchroom that ended in the arrests of 15 evacuees and 12 local students.

The eight suspects arrested Friday and three at large are accused of murder, aggravated robbery, kidnapping and other violent crimes.

All 11 slayings took place in the past three months. Nine occurred in the city’s high-crime southwest side, while the other two were in the Houston suburb of Pasadena.

“The safety of the city of Houston, its citizens and as well as some of the evacuees depends on us arresting these individuals as soon as possible,” Police Chief Harold Hurtt said.