Primary and high school students in Africa's last absolute monarchy, formerly known as Swaziland, have been boycotting classes and staging low-key protests for the past month.

They are mainly calling for the release of two lawmakers arrested during pro-democracy protests earlier this year, along with better learning conditions and free education.

The army has been deployed "to intimidate, but that has not deterred the students", Lucky Lukhele, spokesman for the pro-democracy Swaziland Solidarity Network, told AFP.

"Today it was reinforced," he added, claiming that 17 students including a seven-year-old, were arrested during Monday's protests.

The Communist Party of Swaziland said at least 10 protesters had been arrested, with one student shot in the leg.

Army spokeswoman Tengetile Khumalo confirmed the deployment but said soldiers were "not an enemy of the people".

This "doesn't mean there is war but just an assistance to the other forces to maintain order", she said.

Mduduzi Gina, general secretary of the Trade Union Congress of Eswatini, said "the pupils are calling for political reforms".

"Having the army... and cops deployed in the schools will worsen the situation in Eswatini," he warned.

Civil society and opposition groups demonstrated in the capitals Manzini and Mbabane in June, looting shops and ransacking properties, some of which belonged to King Mswati III.

At least 27 people died as police clashed with protesters in some of the worst unrest in the southern African country's history.

Roughly 40 schools took part in Monday's demonstrations.