Japanese police pledged Thursday to improve their technology to battle cyber crime, <A HREF="http://news.yahoo.com/s/afp/20070222/tc_afp/japaninternet">which shot up 40 percent</A> last year as fraudsters become increasingly sly.

Police investigated 4,425 cases of online crime last year, an increase from 3,161 a year earlier and about 3.3 times more than five years ago, the National Police Agency said in a report.

Nearly half of the crimes involved fraud, mostly through online auctions, it said.