Animal activists target Vic abattoirs

A heavy police presence has foiled a bid by animal activists to block livestock trucks from entering three Melbourne abattoirs.

Animal Liberation Victoria is holding a 16-hour vigil, which started at 3am on Thursday, at three Laverton slaughterhouses in Melbourne's southwest.

They also planned to "peacefully stop transport trucks crammed with animals heading to slaughter" but police have prevented that happening so far.

The group plans to remain at the abattoirs until 7pm.

Kristen Leigh from ALV told AAP that police removed protesters from the road when the first truck arrived and mounted police escorted it into the JBS abattoir in Brooklyn.

The activists have had their details taken by police and been threatened with arrest if they continue to block the road, Ms Leigh said.

In previous years, the group says, it has been allowed to stop trucks for around five minutes to take photos and check on animals before police step in, which has not happened this year.

Victoria Police would not comment on their numbers there.