The number of crimes blamed on foreigners almost doubled in the first half of this year, but 10 percent fewer foreigners were investigated for crimes than in the same period last year, the National Police Agency announced Aug. 21.

Police reported that 2,772 foreigners were investigated in 12,309 cases in the first half of the year, adding that they believe criminal organizations headquartered in Hong Kong, Russia and other countries are responsible for a series of crimes.

This year, the number of serious crimes -- including murder, robbery and arson -- stood at 98, 32 more than the serious crimes committed in the same period last year.

Some 61 percent of all criminal cases ascribed to foreigners involved an accomplice or accomplices, a rise of 29 percent from last year, the NPA said.

Chinese suspects made up the largest group investigated in connection with criminal offenses, accounting for about 42 percent, followed by Koreans and Brazilians.

Some 4,100 foreigners were investigated over violations of the special law, such as Immigration Control and Refugee Law violations, the NPA said.

Of this total, 906 were taken into custody while attempting to enter the country illegally, topping last year's annual record high of 679.

Some 234 foreigners were questioned on suspicion of using forged passports, an 86 percent increase over the same period last year.

The NPA said 167, or 71.4 percent, of the suspects were Chinese.