Gardaí arrested 18 students during the fourth day of student protests at the ongoing teachers dispute.
Pupils took part in protests in Dublin, Cork, Waterford, Tipperary, Sligo and Mayo despite hope of a resolution to the deadlock.
Ten people were arrested in separate incidents throughout Dublin, including four students arrested, and later released, after throwing bottles at the gardaí outside Leinster House.
The pupils, who were part of a larger group of 400 protesters outside the Dáil, were not provoked according to a Garda spokeswoman.
The Dáil usher received facial cuts in a struggle with a student who broke through the security cordon. He was treated in hospital for his injuries.
Five students were also arrested during protests in Artane, Bray and Ballyfermot. All were later released. Another male youth was arrested in Ballyfermot in an incident arising from the protest.
Six students were also arrested in Sligo when about 1,000 students gathered to protest. While in Waterford three students were arrested in Waterford during a protest march at John Roberts Square of 300-400 students.
Up to 1,000 students also gathered in Cork city outside the City Hall. The students handed a letter to Lord Mayor PJ Hourican, calling for an end to the teachers' strike. The protest passed without incident.
This morning pupils of Summerhill College in Sligo town walked out of their morning classes in what was described as a "peaceful protest".
According to a school spokesman the pupils supported the ASTI's demand for a 30 per cent pay increase but were unhappy at the length of the dispute and its adverse effect on their education.
A spokeswoman for the ASTI said teachers regretted today's events. She said: "Teachers are also concerned about the duration of the dispute but those kind of activities will not help anything."
A spokesman for the Department of Education Mr Brian Duggan told ireland.comthis morning the Minister for Education Dr Woods understood student's frustration but urged them to use their time wisely and prepare for exams.
Mr Duggan said the Department was now optimistic a breakthrough might be achieved with the ASTI as a result of talks due to restart on Sunday at the Labour Court.
The talks will involve talks on clarification of the Labour Court recommendation issued two weeks ago.
Yesterday Dr Woods said if the talks made progress he hoped the ASTI teachers would be back at work in time for the Leaving and Junior Cert exams.
Fine Gael spokeswoman for housing and local government, Ms Olivia Mitchell expressed her concern over the protests this evening - saying the protests outside Leinster House was nothing more than "out of control thugs".
She said the behaviour of "hoodlum students" served no purpose to the majority of pupils and warned it would under the public sympathy for students caught in the middle of the teachers' dispute.
"This kind of anarchical behaviour is unacceptable no matter what the cause or the provocation," Ms Mitchell said.