By Kylie Morris BBC Kabul correspondent

The United Nations says it will send tents to help girls continue their education in a northern Afghan province after their two schools were burnt down.

The incident has left 150 girls without a school, their blackboards and books turned to ash.

Unicef had provided funding to establish the schools, just 20 kilometres (12 miles) from the capital of Sar-i-Pul province.

The United Nations and local authorities are continuing their investigation into last week's fires.

But now a local commander says four men have been arrested. He described them as religious leaders and accused them of having links to the Taleban.

Pressure on women

The fires followed the distribution of pamphlets around mosques in the local district warning women against casting off their burqas.

The burqa is no longer compulsory for women

There was a similar campaign in May in the southern city of Kandahar, when pamphlets were distributed warning parents not to send their daughters to schools.

The latest attacks in Afghanistan's north come almost exactly a year after the United States began a bombing campaign in the country to oust the Taleban government.

Under Taleban rule it had been compulsory for women to enclose themselves inside burqas, and girls were prevented from attending school.

The role of women and girls in Afghan society remains a focus for those who would reassert fundamentalist control over Afghan values.