BAGHDAD, Iraq — The Baghdad security operation has been under way less than three weeks, but it has already registered a success: a sharp drop in the number of bullet-riddled bodies found in the streets — victims of sectarian death squads.

The number of bodies found so far this month in Baghdad — most of them shot and showing signs of torture — has dropped by nearly 50% to 494 as of Monday night, compared with 954 in January and 1,222 in December, according to figures compiled by the Associated Press.

Since the crackdown was formally launched February 14, a total of 164 bodies had been found in the capital as of Monday, according to AP figures, which are compiled from police reports. The AP count showed 390 bodies were discovered in the same period in January.

“The intensive security measures have forced the gunmen to leave Baghdad and quit throwing bodies in the streets,” said Kamil Abdul-Nour, a 42-year-old Sunni teacher. “Still, I am afraid that this phenomenon will appear again if the security measures end,” he said.

The American military has boosted the number of U.S. troops working with the police — and Mahdi army chief Moqtada al-Sadr pulled many of his fighters off the streets under pressure from Prime Minister al-Maliki, his political ally. American commanders have also said Sunni and Shiite extremists were shifting from the capital to surrounding provinces such as Diyala.

All that may have also led to a drop in the execution-style killings.

Bombings and other violence continue in the capital despite the crackdown; yesterday, a roadside bomb on the southwestern outskirts of the city killed three American soldiers.