The Senate of Alabama has voted to allow a church to have its own police force.

Legislators on Tuesday voted 24-4 to grant Briarwood Presbyterian Church in Birmingham, Alabama permission to establish its own law enforcement department, according to AP.

The church said it requires its own police force to keep its congregation, which numbers over 4,000, safe.

'We've got over 30,000 events a year that take place at Briarwood - going on all day, all night, at the school, at the church, at the seminary,' Attorney Eric Johnston who drafted the bill told AL.com in February.

'We have to hire policemen all the time. It would be so much easier to have someone on staff.'

Critics of the move say a personal police unit beholden to the church could be used to cover up criminal activity. Law enforcement experts have reportedly said that such a department would be unprecedented in the US.

Alabama has previously given some private universities the right to create their own police forces, but has never extended the option to non-school entities or churches.

A similar bill is scheduled for debate in Alabama's House of Representatives next Tuesday.

Recent years have seen increased concern about security in churches. Last year Mississippi Governor Phil Bryant signed a gun rights bill called the 'Mississippi Church Protection Act'. The legislation allowed churches to create security programmes designating members to carry firearms to defend worshipers against violence.

The state of Alabama has been caught in controversy this week, with Governor Robert Bentley resigning on Monday, pleading guilty to two misdemeanors regarding campaign finance violations. His resignation ends a year-long scandal that has beleaguered the state government.

'I have decided it is time for me to step down as Alabama governor,' said Bentley at a news conference in the state capital of Montgomery. He said his service as Governor 'was a calling that God placed on my life.'

Additional reporting by Reuters