Iran hanged 21 men Wednesday in the latest round of group executions in the past few months, state media reported.

Seventeen convicted drug smugglers were hanged in northeastern Iran, about 620 miles from the capital, Tehran. The region borders Afghanistan, the source of much of the world's heroin.

"After legal procedures, 17 individuals were hanged on the charges of drug smuggling in Khorasan Razavi province this morning," state television reported.

In a separate execution, four others were hanged in southern city of Shiraz, about 497 miles south of Tehran.

"They were hanged on the charges of smuggling and armed robbery," state radio quoted Heidar Asiabi, the Shiraz prosecutor, as saying.

Over July and August, Iran hanged 21 other people on charges of rape, robbery and kidnapping, which along with drug trafficking, are all capital offenses in Iran.