Large crowds gathered in Belfast City Centre on Saturday afternoon for a protest.
As the Christmas Market opens, hundreds also met at the front of City Hall to protest against mandatory vaccination passports.
Motorists were advised that Donegall Square North in Belfast city centre was closed due to "a large gathering" and police asked them to seek an alternative route for your journey.
It has since re-opened, a police update confirmed.
Trafficwatch NI added: "No access now to Wellington Place for vehicles due to a protest at front of Belfast City Hall - seek another route."
On Wednesday, a majority of Stormont ministers backed the Covid certification scheme despite DUP opposition.
It will see legal enforcement of coronavirus status entry requirements for nightclubs, bars, restaurants and a range of other settings from December 13.
Under the compulsory certification scheme, people wishing to gain entry to designated venues would need to demonstrate evidence of Covid-19 vaccination, a negative lateral flow test result, or proof of a coronavirus infection within the previous six months.
On Thursday night, Health Minister Swann circulated a paper to ministers proposing a series of new measures.
The paper includes a recommendation to strengthen work from home guidance, more robust enforcement on face mask wearing and a “scores on the doors” type system to rate how compliant businesses are with Covid rules and mitigations, reports PA news agency.
