Web activists Anonymous have reportedly posted a chilling video calling for the parents of a boy who fell into Harambe the gorilla's pit at Cincinnati Zoo to face charges and be investigated. The video even gives the address and phone number of the pre-school where the boy's mother, Michelle Gregg, works — along with a photograph of her employer's building, on Thursday 2 June.

The 17-year-old gorilla was shot dead when the four-year-old boy managed to wriggle through barriers and fell into his pit. Many animal lovers were outraged, claiming the gorilla was showing no sign of aggression and seemed to be protecting the child. However zoo keepers said they had to shoot to kill as a tranquiliser would have taken up to 15 minutes to work as gorillas are incredibly strong — capable of crushing a coconut with one hand.

Now there are calls for the parents of the child, Michelle Gregg and Deonne Dickerson, to face charges — demands backed by Anonymous. In a video message a member of the group wearing the usual face mask and a disguised voice says: "Dear citizens of the world, as you may have heard an endangered silverback gorilla, Harambe, was killed this week after a woman, Michelle Gregg, neglected to supervise her children.

"We do not see Michelle Gregg as a fit parent. We are calling on an investigation of Michelle Gregg and the zoo. We believe she should be charged in the death of an endangered animal. We are encouraging every able-bodied person watching this video to participate. #OpHarambe engage."

It has also emerged that Deonne Dickerson has a long criminal record and had spent at least a year behind bars. However, Gregg defended herself saying they had only let the boy out of their sight for a moment. On Facebook she wrote: "As a society we are quick to judge how a parent could take their eyes off of their child and if anyone knows me I keep a tight watch on my kids. Accidents happen but I am thankful that the right people were in the right place today."

Apparently referring to the racist tone of some of the criticism against the parents, the Anonymous spokesman says racist comments against the couple are unacceptable and will also be dealt with. However on social media some people were dismissive of the group nominating itself as a judge of what constitutes good or bad parenting.

Completely lost all respect and support for #Anonymous over this #opharambe nonsense. This is a witch hunt&they should be ashamed. June 2, 2016

"You're not Anonymous," said one Facebook poster. "Anonymous don't bully people that had an accident. Are you going to harass every parent that lost their kid? Then start with me. I lost my kid at a carnival, and got lucky and found him before disaster struck. Every parent loses their kid at one point or another. It happens. Did you always do everything your mom said? Obviously not."