LOS ANGELES (AP) – Police raided the city’s skid-row area where many homeless people reside and arrested more than 130 people, some of whom are ex-convicts who had violated parole, authorities said.

Police rousted the people they were searching for in the city’s skid-row district south of downtown. Of those taken into custody Wednesday, about half were found inside buildings, while the others were on the streets. About 40 percent of the cases involved parolees found to be in possession of narcotics or weapons, authorities said.

Police officers were accompanied by parole officers who had gathered information about parolees by conducting surveillance. Authorities did not approach people randomly.

“This operation was not aimed at the homeless population; rather it was aimed at many of those who seek to victimize the homeless,” said Lt. Horace Frank, an LAPD spokesman. “Those arrested were found to be in possession of heroin, rock cocaine and other contraband, including weapons.”

The number of arrests quickly overcrowded the jail facilities at Parker Center, the LAPD’s headquarters, and forced police to use buses as temporary detention housing.

Officials estimate that 9,000 to 15,000 people live on Los Angeles streets and as many as 3,000 to 5,000 of them on skid row. The area “has the highest concentration of parolees in the state, almost 2,000,” said police Capt. Charles Beck.