A group of 13-year-old girls from Nelson Mandela Bay's elite Collegiate High School have landed in hot water after being caught sipping vodka and watching a pornographic video - allegedly of one of them having sex with her boyfriend - on a cellphone.

Hours after the four girls, all in Grade 8, were caught by a school monitor last week, news of the incident was plastered all over social networking websites such as Twitter and Facebook - much to the shock of parents and the ire of the school.

Acting Collegiate headmistress Faith Biggs was fuming over the posting of the incident on the internet.

"It was all over Facebook a half hour after it happened," she said yesterday.

"Unfortunately, we have silly girls who go onto Facebook and Twitter. By 5.30pm all of my governing body's parents knew about this."

Child specialists have warned that the trend of younger children being exposed to pornography, and subsequently exploring their sexuality, is becoming commonplace because of the proliferation of cellphones and a lack of gate-keeping measures by technologically naive parents.

The four girls have reportedly been banned from attending matric farewells or valedictory services, and the carol festivities at the Feather Market Centre, held at the end of every year, for the rest of their school careers.

They have also been put on indefinite Saturday detention and have been banned from participating in school sports.

According to Collegiate pupils and their parents, the girls smuggled in a mixture of condensed milk and vodka in hot-water bottles on Tuesday last week, and sat drinking and watching a video clip of one of the girls having sex with her boyfriend.

But they were spotted by a class monitor, who alerted a teacher, who alerted Biggs.

"The girls were taken to the principal's office, where the parents were called in and the parents then viewed the clip," said a parent, who asked not to be named.

The only official indication from the school that anything untoward had occurred was the announcement of a ban on all liquids being brought onto the school grounds. But because the ban's effectiveness was dubious, it was repealed a day later, said pupils and parents.

Biggs said yesterday that she had been "putting out fires all over the place".

The school released a statement that read: "On October 26 it was reported to the Grade 8 head by one of the pupils that alcohol was allegedly consumed on the school property prior to the beginning of the school day and some girls were viewing pornography on a cellphone.

"A meeting was immediately called with the offenders and their parents where they were advised that these offences carried a maximum sanction of expulsion if confirmed by the department of education. After consultation with all relevant stakeholders and having regard to the offenders' unblemished student record, and the imminence of the final examinations, a decision was taken that the matter be dealt with internally in accordance with the school's disciplinary code of conduct."

The father of a Grade 9 pupil said the girls were disciplined appropriately.

"When you're 13 or 14 years old, you do silly things," he said.

Eastern Cape Childline director Anna Louise Olivier said parents should immerse themselves in modern technology to better keep an eye on what their children were up to.