UPDATED | June 18, 2017, 10:33PM

LONDON (CBSDFW.COM/CBSNEWS) – One person was arrested after a vehicle struck pedestrians in London early Monday which caused “a number of casualties,” London police said.

A vehicle struck pedestrians in London, causing “a number of casualties,” police say. (Sky News via CBS News)

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Metropolitan Police tweeted they were working on a major incident near Seven Sisters Road in London.

“Officers are on the scene with other emergency services,” the statement said. “There are a number of casualties being worked on at the scene. There has been one person arrested. Enquiries continue.”

The U.K. Muslim Council of Britain said they had been told worshippers were ran over as they left a local mosque. “Our prayers are with the victims,” they said on Twitter.

One witness told Sky News that the incident happened after worshippers were leaving the Finsbury Park mosque after midnight prayers.

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Another witness, who lives near the scene, told the BBC she heard screaming from her residence. “From the window, I started hearing a lot of yelling and screeching, a lot of chaos outside. Everybody was shouting: ‘A van’s hit people, a van’s hit people.’ There was this white van stopped outside Finsbury Park mosque that seemed to have hit people who were coming out after prayers had finished.”

U.K. Prime Minister Theresa May has described the situation Monday as a “terrible incident.”

“All my thoughts are with those who have been injured, their loved ones and the emergency services on the scene,” she said in a statement.

Jeremy Corbyn, the Labour Party leader, also said that he was “totally shocked” by the event. “I’ve been in touch with the mosques, police and Islington council,” he said in a statement on Twitter.

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This is a developing story and will be updated.