WARSAW, Poland (AP) — Middle school students in Poland took important exams Wednesday even though a nationwide teachers' strike entered its third day, forcing exam authorities to ask for help from retired teachers, religion tutors and those not on strike.

The exam in humanities for around 350,000 students was held in all schools but one, in the western village of Owinska, where extra help for the exam team wasn't provided in time. Tests in mathematics and foreign languages will be held Thursday and Friday.

The indefinite strike began Monday after pay negotiations with the government failed. Teachers' monthly net earnings range from 1,800 zlotys to 3,000 zlotys ($470 to $780).

Deputy Prime Minister Beata Szydlo thanked school directors for making the exams possible and urged striking educators to accept the government's offer, which unions have repeatedly rejected.

Teachers want an immediate 30% pay increase. But the government has said it will accelerate a planned increase of around 15% and introduce a new remuneration system, which would substantially raise salaries but also increase the number of lessons a teacher gives a week to 24 from the current 18.

The teachers' unions warned that the nonstandard way the tests were being held could undermine their validity.

Students at a school in Warsaw who spoke to The Associated Press didn't think that the strike added to their stress and said they supported the teachers' demands for higher pay.