Washington - The number of murders committed in the US by black teenagers increased 34 per cent between 2000 and 2007, while those committed by whites had barely changed, a report to be released Monday by Northeastern University in Boston said.

In 2000, 539 white and 851 black youths between age 14 to 17 committed murder, according to a story about the report in the New York Times. By 2007, the number of murders by blacks had risen to 1,142 while those committed by whites had fallen slightly, to 537.

The authors of the study, James Alan Fox, a criminal justice professor at Northeastern University, and Marc Swatt, attributed the increase in the murder rate among black teenagers to the drop in federal support to keep more police officers in the streets and to expand social programmes for poor youths.

"Regrettably, as the nation celebrated the successful fight against violent crime in the 1990s, we grew complacent and eased up on our crime-fighting efforts," the authors were quoted as saying. (dpa)