LIVERPOOL, England >> Three people were arrested in connection with a plan by animal rights activists to disrupt the prestigious Grand National horse race on Saturday.

All three were arrested on “suspicion of conspiracy to cause public nuisance,” Merseyside Police said.

A 25-year-old woman and a man were arrested while protesting outside Aintree racecourse near Liverpool, where the famous steeplechase takes place.

Earlier Saturday, a 33-year-old woman was arrested in the Greater Manchester area “in connection with potential coordinated disruption activities” at Aintree, police said. Their names were not disclosed.

Animal Rising had called on protesters to gather outside the racecourse to demand an end to “animal cruelty for entertainment.” The group tweeted a video that it said shows one of its spokespeople being arrested at the protest.

Police said they have been working with race organizers ahead of and during the Grand National Festival, which started Thursday.

“We are aware of some people planning to protest at the event,” a police spokesperson said in a statement. “This has been factored into our plans. We respect the right to peaceful protest and expression of views, but criminal behavior and disorder will not be tolerated and will be dealt with robustly.”

Animal Rising activist Alex Lockwood this week told British radio station talkSPORT that they planned to disrupt the Grand National, arguing that standing outside and handing out fliers “never stopped anything.”

The Grand National, among the biggest occasions on the British sporting calendar, is regarded as one of the most dangerous horse races in the world because of the size of the fences.

Changes were made in 2012 to make the course safer, including softening some of the fences, after two horses died in the Grand National that year and in 2011.

There have been four fatalities from 356 runners in the nine Grand Nationals since.

Four horses died at the Aintree festival last year, including two who were injured in the Grand National. Another horse, Envoye Special, suffered a fatal injury in the Foxhunters’ Chase — run over the fences used for the Grand National — on Thursday.