Seven girls aged between 13 and 14 have fallen pregnant after going on a school trip in Bosnia.

Furious parents are demanding to know why there was such a lack of teacher supervision when the girls, from the town of Banja Luka, returned from a five-day trip to the capital city.

The school had taken 28 girls on the educational outing to Sarajevo to visit museums and other historical sitess, but since returning the girls have now reportedly dropped out of lessons.

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The 28 schoolgirls were on a trip to the capital of Bosnia, Sarajevo (pictured), when seven returned pregnant

The case has provoked nationwide discussions about sex education in Bosnia, where the number of sexually active girls aged between 13 and 15 has increased significantly.

Senad Mehmedbasic, a gynaecologist from Sarajevo said that a growing trend for underage pregnancies in Bosnia is worrying.

'That is the trend of today. But we can not continue to allow our children to be educated about sex on the street and not in school,' he added.

He added that educational institutes and parents should play a stronger role in providing effective sex education.

'It is obvious that children do not have enough knowledge of health education so they engage in such activities, not knowing the consequences.

'We have to be more direct in the educational system, it must not be allowed that street teaches children about intimate matters, and that they are later slapped by life.'

Parents of the girls, who are from the town of Banja Luka (pictured), are demanding to know why the teachers were not providing better supervision on the trip

Young girls in Bosnia are seeking advice from experts online, the InSerba News Network has reported.

One schoolgirl wrote: 'I would have sex with my boyfriend, even though I'm only 14... But I am afraid I'll be judged.'

Last year in Sarajevo 31 underage girls became pregnant but seven out of 28 girls in one five day period has set something of a record.

The National Coordinator for Reproductive Health of the Republika Srpska, Nenad Babici, admitted more children in his country are engaging in sexual relations as early as at age of 13 or 14.