Campaigning in the referendum on Britain's membership in the European Union remains suspended as Britain mourns the killing of Labour Party legislator Jo Cox.

It is not yet clear when campaigning will resume ahead of the vital June 23 vote on whether Britain should remain in the 28-nation bloc.

There were tributes to the 41-year-old Cox across much of Britain Friday.

She was shot to death Thursday afternoon in her constituency near Leeds in northern England. A 52-year-old man has been arrested but has not been charged. He has been named locally as Tommy Mair.

West Yorkshire Police have not offered a motive for the slaying.