That's when one of the men grabbed a brick and struck him across the head, he says.
He fell to the ground and, mercifully, lost consciousness. Because what followed was even worse -- an act that authorities dubbed "pure evil."
"This little child who has his whole future ahead of him, they all but killed him," said Mohammed Sohail, a commander with Bangladesh's elite anti-crime unit, the Rapid Action Battalion. "They thought he was gone. Dead."
The attackers left Okkhoy by the side of a warehouse, intending to come back later and dump him in the river.
His mother, who had gone looking for her missing child, found him.
"I barely recognized him; he was so stained with blood," she remembers.
With every ounce of energy she could muster, the hysterical mother carried Okkhoy's limp body to the side of the main road. "Who killed my baby? Who killed my baby?" she wailed.
Abed, alerted by a neighbor, rushed to the scene -- and the gory sight.
"It felt like the sky fell on me," he says. "As a father, there is no greater pain in the world than knowing that you could not protect your child."
Okkhoy spent three months in a Dhaka hospital, where doctors stitched up his wounds. But they were unable to do much to repair the severed organ.
A despicable practice
For most Westerners, the issue of forced begging was thrust into the spotlight in the 2008 Oscar-winning movie "Slumdog Millionaire," in which a child in Mumbai, India, is intentionally blinded so he could bring in more money in alms.
But the existence and prevalence of "beggar mafias" is an open secret in South Asian countries.
So, the gangs kidnap and cripple children -- knowing sympathetic passersby are more likely to be touched by, and give to, a limbless child.
Almost half of Bangladesh's 150 million people live on less than a dollar a day. The economy has slowed; poverty is skyrocketing.
And each new day brings a fresh batch of sun-caked boys and girls who tap on car windows to draw attention to their disfigurement -- a desperate way to survive.
The U.S. State Department, in its 2012 Trafficking in Persons report, cited forced begging as one of the areas where Bangladesh needs to develop a comprehensive approach of prevention and prosecution.
Begging is banned in the country -- at least in its penal code. And a three-year prison term awaits anyone caught forcing someone to beg.
But enforcement is lax and for now, the ring masters in this cruel circus remain above the law.