Hotels in the Italian city of Assisi are doing their bit to boost the country's flagging birth rate by offering a free holiday to couples who conceive there.

Ten hotels are offering refunds or a free future stay to guests who fall pregnant under the Fertility Room campaign.

Guests will simply have to produce a birth certificate to prove the baby was born around nine months after their stay in the medieval city.

"Giving birth to a child is an act of deep love, which should be encouraged despite the multitude of difficulties in life," organizers said as the campaign launched on Friday.

Local tourism councillor Eugenio Guarducci, the man behind the initiative, said the aim was to encourage travel to the Umbrian town in central Italy -- the birthplace of Saint Francis -- and help reverse Italy's low fertility rate.

Italy has the lowest birthrate in the European Union and one of the lowest in the world, with only eight babies born for every 1,000 residents in 2015, according to EU figures released in July.