Hundreds of teachers from private high schools in this western China city called a strike this week to protest low salaries and deplorable working conditions.

On Thursday afternoon, teachers at the Chengdu Foreign Languages School, owned by the Chengdu-based Derui Group, had a dialogue with Yan Yude, chairman of the group, who is in this year's list of the richest men in China. Teachers asked for a pay rise, and Yan offered an increase of 1,000 yuan (US$147) per month for the average teacher.

Teachers rejected Yan's proposal, saying many State-owned schools in the city had recently given their teachers a monthly pay raise of 3,000 yuan per month, said Ma, a renowned teacher of English in the city.

Yan responded that the teachers should go ahead and resign, and that he was not scared of their threats because he had thousands of potential teachers to choose from for his school.

Yan's wife, Wang Xiaoying, snatched the microphone and accused the teachers of being low quality, caring only for money and not being fit for teaching jobs.

The couple refused to apologize to the teachers, and Wang uttered more curses at them. Yan threatened the teachers that they would have to "bear all the consequences" of their petition. This prompted about 400 teachers to strike at around 2 pm.

Showing support for their teachers, students left their classrooms in the evening to stage a protest, chanting slogans.

When the news of their strike spread to the Chengdu Experimental Foreign Languages School, some 250 teachers there started a strike around 3 pm Thursday. The strike continued yesterday.

"The school asked our parents to take us home, citing H1N1 flu prevention," said a fourth grader surnamed Li.

Since the Chengdu Experimental Foreign Languages School, a former State-owned school, became a private one in 2002, teachers have not had a pay increase despite their repeated requests, Li said.

"Even the best teacher there earns only 2,500 yuan (US$368) a month, which is the pay plus the bonus," Li told China Daily.

The teachers' working conditions are awful as their offices are in a makeshift house on the sixth floor of a school building. "When we step into it, we feel it is trembling," said Wang, another fourth grader.

The students joined in the protest not only because the teachers are kind but also because of their own deplorable treatment, Li said.

They pay 500 yuan for 20 days of eating in the canteen each month. The food is substandard and Li found parts of a cockroach in her food on Thursday.

Each year, the school only allows students to turn on air-conditioners in their dorms just a few times. Dead rats have been found on air-conditioners in classrooms, Wang said.

Police forced reporters who took pictures outside the gate to delete the pictures of teachers demonstrating.

Both schools have asked teachers to resume work on Sunday so that they can start teaching next day. But no teachers have promised to return as no deal has been made between them and the Derui Group.

Teachers in both schools have sent a letter of apology to the students and their families and vow to make up the missing lessons free of charge.