France, Oct. 1 -- Around 30 university campuses were blocked on Thursday morning, the Union Etudiante (Student Union) said, including sites in Paris, Strasbourg, Marseille, Lyon, Reims, Poitiers and Nanterre.

High schools were also blocked in several cities.

The movement began in high schools about a week ago and had spread to 356 schools across the country by Wednesday, the Interior Ministry said.

Student grievances range from timetables, class sizes and a shortage of teachers to overheated classrooms during this year's heatwaves. Widening mobilisation

On Thursday, hundreds of pupils in Strasbourg blocked traffic and a tram line outside Couffignal high school and set rubbish containers on fire. In Saint-Denis, north of Paris, clashes...