BAGHDAD, April 2 — A day after members of an American Congressional delegation led by Senator John McCain pointed to their brief visit to Baghdad’s central market as evidence that the new security plan for the city was working, the merchants there were incredulous about the Americans’ conclusions.

“What are they talking about?” Ali Jassim Faiyad, the owner of an electrical appliances shop in the market, said Monday. “The security procedures were abnormal!”

The delegation arrived at the market, which is called Shorja, on Sunday with more than 100 soldiers in armored Humvees — the equivalent of an entire company — and attack helicopters circled overhead, a senior American military official in Baghdad said. The soldiers redirected traffic from the area and restricted access to the Americans, witnesses said, and sharpshooters were posted on the roofs. The congressmen wore bulletproof vests throughout their hourlong visit.

“They paralyzed the market when they came,” Mr. Faiyad said during an interview in his shop on Monday. “This was only for the media.”