"Everybody is living in fear of this guy at home, but here, he's getting good treatment!" said Yemeni immigrant Nasser Almroot, a Brooklyn grocer.
The dozen angry protesters were kept behind police barricades across the street from the Ritz-Carlton hotel, which was teeming with security guards, both inside and on the sidewalk where Saleh passed.
The 69-year-old leader is visiting the United States for medical treatment.
He exited the hotel on Central Park South on Sunday afternoon and waved and smiled sardonically toward the yelling protesters - even blowing them a kiss. Suddenly, one of them tried to charge across the street but was restrained by police, who wrestled him to the ground.
"He can't help it, the killer is here," Almroot said.
As the man bolted out, a shoe flew in Saleh's direction. Showing the sole of a shoe is an insult in Arab culture, because it is on the lowest part of the body, the foot. To hit someone with a shoe is seen as even worse.
Saleh got into his car and his motorcade left for an unknown destination.
Since he arrived in New York about a week ago, the Yemeni president has kept a low profile.
His presence, however, has been controversial.
On Sunday, the protesters hoisted placards bearing photos of Yemenis badly bloodied and brutally killed during his government's yearlong crackdown on anti-Saleh demonstrations.
He signed a deal in November to transfer power to his vice president in exchange for immunity from prosecution.
An election is scheduled on Feb. 21 to select his successor in a nation mired in poverty and divided among powerful tribes and political factions.
While Saleh has been an anti-terrorism ally of Washington, the United States has not officially welcomed a leader accused of killing hundreds of people during an uprising against his 33-year rule.
Saleh traveled to the United States with permission for a private visit.
In June, he was badly injured in an attack on his presidential palace - an assassination attempt after which he spent months in Saudi Arabia being treated for massive burns from the explosion that ripped through his palace mosque as he prayed.
A world-renowned burn center is in Manhattan, at the NewYork-Presbyterian Hospital/Weill Cornell Medical Center. Hospital officials have not confirmed whether Saleh was a patient there.
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