The British Museum was forced to shut its doors early due to a protest against climate change and in support of Palestine.
The London institution said on its website that it closed at 2.45pm on Sunday following demonstrations outside by Energy Embargo for Palestine.
Visitors who entered the building prior to the protests were still inside as people demonstrated outside, the PA news agency understands.
A British Museum spokeswoman said: “The British Museum respects other people’s right to express their views and allows peaceful protest onsite at the museum as long as there is no risk to the collection, staff or visitors.”
The museum closes at 5pm every day except Fridays, and those who bought tickets will be given a refund or have their visit moved to another day, it is understood.
In a statement, Energy Embargo for Palestine said: “Over two hundred activists staged a mass disruption on the pavement outside of the main entrance of the museum.”
The group, which previously organised a protest at the Great Court alongside the Palestine Solidarity Campaign, objects to the museum’s partnership with BP.
The campaigners accuse BP of attempting to “greenwash” its actions by sponsoring the museum.
They also objected to the British Museum confirming in December that BP will sponsor the museum for another decade following a £50 million deal to help fund its renovations plans.
Energy Embargo for Palestine said the museum “is the main platform for the social licence of BP, legitimises its philanthropic efforts, and enshrines its image of corporate responsibility and contribution to British society and culture”.
It has cited six companies including BP being given gas exploration licences for off the coast of Israel, according to an October announcement.
The Metropolitan Police confirmed the force attended and there were no arrests.
It is understood the force advised for the building to be closed to the public.
BP has been contacted for comment.