DUBLIN/BRUSSELS: Border inspections at two Northern Irish ports were suspended on Tuesday, after staff were threatened over contentious new Brexit controls in the long-divided British province.

The development comes just over a month into new trading arrangements after Britain’s departure from the European single market, and warnings they could stoke lingering sectarian sentiment in Northern Ireland. The European Commission said staff working at the two border posts in Northern Ireland were also told “not to attend to their duties” on Tuesday after the “threat of violence” prompted regional authorities to pull staff from ports.

Northern Ireland’s Department of Agriculture, Environment and Rural Affairs, said late Monday that regulatory animal-based food checks were dropped at Belfast and Larne ports “in the interests of the wellbeing of staff”.

At Larne Port, the local Mid and East Antrim Borough Council withdrew 12 staff after “an upsurge in sinister and menacing behaviour in recent weeks”, with hardcore unionists blamed.

The council cited “the appearance of graffiti within the local area referencing increasing tensions around the Northern Ireland Protocol and describing Port staff as ‘targets’”.

Regional media reported that attempts seemed to have been made to collect information on staff, including vehicle registration plates, in acts of intimidation recalling the darkest days of “The Troubles” in Northern Ireland.

The Northern Ireland Executive — formed under a power-sharing agreement between pro-British unionist and republican parties who want a united Ireland — jointly condemned the situation.

Police patrols have since been stepped up, while Northern Ireland’s leaders are due to talk to UK and EU ministers on Wednesday.

The Northern Ireland Protocol came into effect on January 1, when the Brexit transition period ended and the full effects of the UK’s 2016 decision to split from the EU were finally felt.

The protocol is designed to prevent a hard border emerging between Northern Ireland and EU member the Republic of Ireland — a frequent flashpoint in three decades of violence over British rule.

Up to 1998, some 3,500 people were killed as unionists who favoured ties to Britain engaged in a deadly tug-of-war with republicans seeking to merge the province with Ireland.

Security checkpoints and patrols along the 500-kilometre (310-mile) border were targeted by republican paramilitaries in some of the bloodiest chapters of the sectarian violence.

Post-Brexit, London and Brussels feared splinter republican groups still active after the 1998 Good Friday Agreement peace deal could target checks and use them as a recruiting tool to grow their base.