A carriage horse has been euthanized after a disturbing video showed it collapsing in New York City's Central Park over the weekend. The incident has reignited calls to ban horse-drawn carriages in the city.

The footage, which was provided by animal advocacy group NYCLASS to CBS News, shows a horse called Aisha unable to stand by itself after collapsing on Saturday afternoon. Its handlers attempt to lift the horse, but are unable to as its back legs appear to be too weak. At one point, a man smoking is seen blowing smoke into the horse's face. Eventually, the horse is placed into a vehicle be transported away. 

New York City Mayor Bill de Blasio, who made a campaign pledge to ban horse carriages during his first mayoral race, called the scene in the video "painful." "We've made real progress in animal welfare but we must go further," de Blasio tweeted Sunday. "The NYPD's Animal Cruelty Investigation Squad is on the case and WILL get answers."

New York City Mayor Bill de Blasio, who made a campaign pledge to ban horse carriages during his first mayoral race, called the scene in the video "painful." "We've made real progress in animal welfare but we must go further," de Blasio tweeted Sunday. "The NYPD's Animal Cruelty Investigation Squad is on the case and WILL get answers."

Edita Birnkrant, executive director of NYCLASS, believes there was an underlying medical issue with Aisha and called the incident "abuse." 

"It's very clear that it's not possible for horse carriages to operate in NYC without causing tremendous suffering, cruelty and abuse to the horses," Birnkrant told CBS News.

Christina Hansen, a spokesperson for the NYC carriage industry, told CBS News in a statement that the 12-year-old mare was healthy and likely suffered from a "cardiac event."

"Animal rights extremists are already exploiting this tragedy to further their anti-horse agenda during our time of grief and shock," Hansen said. "This medical emergency appears to be something that could happen to any horse, any time, anywhere, for any number of reasons, under a wide variety of conditions."