Night weddings have been banned in Kenya's coastal region of Mombasa as the authorities say they have become a target for criminals.

The county's commissioner said the decision was taken after an increase in attacks by knife-wielding gangs.

Wedding ceremonies in Mombasa can last for as long as five days and include parties that go on late into the night.

The ban came into effect immediately and celebrations had to end by 22:00 local time, the commissioner said.

Families who wanted a wedding to continue after this time would have to get police clearance and pay a fee for armed officers, County Commissioner Maalim Mohamed said.

The move comes after a group of women were attacked and their valuables were stolen after they left a night-time wedding, Kenya's Citizen newspaper reports.

The BBC's Ferdinand Omondi in Mombasa says police have recently been carrying out security operations and several suspected gangsters have been shot dead.

A critic of the directive called it "archaic".

"The government cannot ban night weddings, which are cultural in this region," Julius Ogogoh, who heads the non-governmental organisation Commission for Human Rights and Justice, told the Daily Nation newspaper.

"Instead, security agencies must deal with the gangs. We are in the 21st Century and such orders are archaic."