Children as young as five are being suspended from school in increasing numbers while exclusions among girls have doubled over the past six years, according to a new report.

Official figures show 5779 pupils were excluded from Scottish primaries in 2005-06, a 9% increase on the previous year - with substance abuse, sexual harassment and gang-related incidents amongst the reasons - raising fears that discipline problems in Scottish secondaries are now spreading to the primary sector.

Girls accounted for 11% of all exclusions from Scotland's schools in 1999, but last year the figure increased to 22%.

The proportion of young girls referred to the Children's Reporter over the last 10 years has increased from 35% to 42% with the increase being put down to "ladette" culture.

The rise at primary level follows recent warnings that a generation of very young children with severe behavioural problems and a lack of basic social skills is entering Scotland's schools.

Last year, Peter Peacock, the former education minister, warned of a growing trend for pupils to start primary with little parental bonding, violent behaviour, an inability to communicate with other children and even an inability to eat properly.

In some local authority areas, including Glasgow, councils have introduced special classes for some P1 children to teach them basic social and behavioural skills before they join mainstream classes.

There were nearly 43,000 exclusions from state schools last year, up 2%, and the fourth annual rise since 2003 when the executive dropped the controversial practice of setting national targets to limit suspensions. Secondary school exclusions went up by 2% to 35,513, according to the Scottish Executive report.

Some 31% of the exclusions involved "general or persistent disobedience", 25% involved verbal abuse of staff and 15% for "insolent or offensive behaviour".

Last night, academics and teachers' leaders warned that the rise in exclusions in primary could have a serious impact on discipline in secondary over the next few years.

Professor Eric Wilkinson, an expert in early years education at Glasgow University, said: "This is an area of considerable concern because primary pupils have much more attention from teachers and can develop closer relationships. You would expect that to have a positive impact on discipline.

"When pupils move to secondary they have to deal with many more teachers in a more remote way and that could lead to further problems."

Ronnie Smith, general secretary of the Educational Institute of Scotland (EIS), said he hoped to see a reduction in primary exclusions in future.

"It is a cause of some concern that the problem seems to be growing more rapidly in primary than in secondary and one reason could be that the age of adolescence is dropping.

"However, if nursery education has an impact on the socialisation of children we could see exclusions falling in future years."

Fiona Hyslop, education spokeswoman for the SNP, said smaller class sizes should be introduced into primary schools. "We have deep concerns at this increase in primary schools and it is clear that smaller class sizes would play a big part in combating disruptive behaviour in our classrooms," she said.

However, Hugh Henry, the education minister, said it was important to keep the figures in perspective with just 3% of the total number of pupils excluded. "Our schools are not battlegrounds and the vast majority of pupils are well-behaved," he said.

Charlie Gray, education spokesman for Cosla, which represents local authorities, said it was "heartening" that the number of pupils permanently excluded had fallen.