An outgoing Stormont minister has appealed for calm heads after Brexit port checks were suspended over threatening loyalist behaviour.

Edwin Poots said there is anger in the unionist community over new “disproportionate” Irish Sea regulatory and customs checks required under the terms of the divorce deal’s Northern Ireland Protocol.

Inspections at Larne and Belfast ports were suspended on Monday after sinister graffiti and reports of intelligence-gathering on inspectors carrying out the checks.

Lorries arriving at new inspection facilities at Belfast Port on Tuesday morning were turned around and redirected by Border Force officials.

Police in Northern Ireland will hold talks with inspection agencies later.

Former agriculture minister Mr Poots said: “It is difficult for politicians to (control) the level of anger that is in the community in respect of this and it is a time for calm heads and a time for wise behaviour, but these things have certainly created a lot of tension in the community.”

His officials are among those to be withdrawn.

There is no indication at this stage whether the threat is coming from an organised paramilitary source, rather than an individual or individuals.

The senior Democratic Unionist, who stepped down at midnight ahead of undergoing cancer surgery, added: “Ultimately the people who are doing their jobs, who are going to their work, are not their enemies.

“They are people who are simply carrying out a job, whether it is the Department of Agriculture, the local council or Food Standards Agency.”

He added: “Those people should be allowed to do their jobs in peace. Any threat against them should be withdrawn and allow people to carry on their duties.”

He told BBC Radio 4’s Today programme the tensions are linked to potential curbs on British Army movements across the Irish Sea and follow withdrawn EU threats to restrict vaccine supplies.

Loyalists are angry at the imposition of a new economic border between Northern Ireland and the rest of the UK.

The suspension move came as focus on the protocol intensified following Friday’s ill-fated move by the EU to suspend aspects of its operation amid the furore over vaccine supply in the bloc.

The European Commission swiftly backtracked after facing intense criticism for attempting to hinder the free flow of movement across the Irish border in respect of vaccines.

Irish Taoiseach Micheal Martin told RTE the ports safety concern is a sinister development.

He said: “I would condemn the intimidatory tactics against workers who should of course be allowed and facilitated in going about their daily work.

“It’s a very sinister and ugly development.

“Obviously, we will be doing everything we possibly can to assist and to defuse the situation.”

Mr Poots’ Department of Agriculture, Environment and Rural Affairs (Daera) said on Monday that it had decided “in the interests of the wellbeing of staff to temporarily suspend physical inspections of products of animal origin at Larne and Belfast” pending further discussions with the PSNI.

Full documentary checks will continue to be carried out as usual.

Mr Poots said: “The Protocol, as has been established, has made Great Britain a third country to Northern Ireland when we are all part of the sovereign UK.

“The EU laws that have been established to deal with materials coming in from third countries such as Brazil and Argentina is a totally disproportionate application to have that applied to Great Britain whenever Northern Ireland is part of the UK, remains part of the UK, but over 50% of our trade in foodstuffs is coming from Great Britain and the impact upon the people of Northern Ireland is immense.”

PSNI Assistant Chief Constable Mark McEwan said his officers have increased patrols at Larne Port and other points of entry in order to reassure staff and the local community.

Twelve Mid and East Antrim Borough Council staff assisting officials from Daera and UK Border Force with checks at Larne Port were withdrawn from their duties with immediate effect on Monday.

The council said it followed an “upsurge in sinister and menacing behaviour in recent weeks”.

Graffiti appeared in the area last month, referring to tensions about the Northern Ireland Protocol and describing port staff as “targets”.

There have also been a number of daubings in Belfast amid anger at the protocol, with a raft of new checks on goods arriving at ports from Great Britain introduced at the start of the year.

In addition to fears over graffiti, it is understood staff expressed concerns that individuals had been spotted taking down number plate details.

Police last month warned that discontent in loyalist communities was “growing” over the Northern Ireland Protocol, which is designed to allow the country to follow the EU’s customs rules and has caused delays at ports because of new declarations and checks, but said their feedback was not causing significant concern.