A man and a woman, the latter aged 25 and from London, were arrested outside Aintree Racecourse on suspicion of conspiracy to cause public nuisance shortly before midday.

Earlier, a 33-year-old woman from London was detained in Greater Manchester on suspicion of the same offence.

It comes after Animal Rising activists said they were planning to scale fences and storm the track, with up to 300 protesters planning to attend.

Others plan to block traffic by performing a slow march along the main access route outside Aintree Racecourse.

Ahead of the arrests, Merseyside Police had warned they have a "robust policing plan in place" and were working with Aintree's owners, The Jockey Club, in preparation for any incidents.

'Horses will likely die'

Animal Rising had revealed its plans to disrupt the event in advance.

Spokesperson Nathan McGovern said: "Animal Rising intends to make sure the Grand National doesn't even begin.

"We know that if the race begins, then horses will likely die as Eclair Surf and Discorama did last year. People will attempt to put their bodies between horses and harm by calling the entire race off."

The group cites figures from campaigners at Animal Aid that suggest a horse dies every two to three days in UK racing, with Mr McGovern adding: "We want to see an end to that."

He went on to stress that activists plan to act before the race starts, and they would not enter the track if horses and jockeys are riding.

Speaking live from Aintree Racecourse on Sky News Breakfast, Animal Rising spokesperson Claudia Penna Rojas reiterated it would be a "completely non-violent" protest.

Activists will be demonstrating outside the racecourse before "peacefully" making their way towards the track, she said.

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One horse has already died at the Grand National Festival - Envoye Special - after it fell in the Foxhunters' Chase just after 4pm on Thursday.

It is the 60th horse to have died at Aintree in the past 23 years.

Animal Rising was formerly known as Animal Rebellion, but changed its name earlier this week in order to move away from the umbrella of Extinction Rebellion.

It plans to target the Grand National were made public when an undercover reporter attended a meeting earlier this month.

According to The Mail on Sunday, activists are intending to use ladders and bolt cutters to get through the perimeter fencing at Aintree.

Mr McGovern added: "It's a spotlight that we really need to be using to push a national conversation about our broken relationship, not only with horses but with all the animals that we use, whether that's for food, fun, entertainment and dog and horse racing.

"This is very much about a bigger picture of recognising that, in a nation of animal lovers, we're not really living up to those values with our actions."

A Merseyside Police spokesperson said: "We respect the right to peaceful protest and expression of views, but public order or criminal offences will not be tolerated and will be dealt with robustly."

Meanwhile, an Aintree Racecourse representative urged Animal Rising to "reflect on whether their proposed actions are legitimate and responsible".

They added: "Their actions could endanger the horses they purport to protect, as well as jockeys, officials and themselves."