Teachers in Colombia are leading strikes across the country in protest of what they describe as unfair working conditions, low pay and subpar healthcare plans. Negotiations between the government and members of local teachers’ unions were unsuccessful last weekend, said union ombudsman Jorge Armanda Otalora, who served as mediator during the talks, Latin American news site Telesur reported.

The two sides were unable to reach a compromise after 20 hours of discussions that began Sunday and ended Monday morning. The country’s Finance Minister Mauricio Cardenas said the Colombian government was willing to increase teachers’ salaries by 12 percent. Teachers union Fecode declined the offer, claiming it didn’t meet enough of the teachers’ demands.

Thousands of teachers have been on strike since April 22. They have refused to return to work until their demands are met. Union members say they want improved healthcare, salary increases and the elimination of stringent evaluations for teachers. Many also hoped that the Colombian government would increase its investment in public education.

This isn’t Fecode's first attempt at negotiations. The union held 50 days of talks with the government before its members abandoned classrooms in April. According to union data, teachers in the country's public schools receive an average monthly salary of 1.2 million Colombian pesos (about $509).

Most of the teachers are primary or secondary public school teachers. The movement has gained support from more than 300,000 teachers across the country. The strike has left around 9 million children without classes since late April.

Many supporters of the teachers participated in demonstrations on Colombian streets last week, particularly on Friday, which marked International Workers’ Day, or May Day. Local media reported that the demonstrators were peaceful, though a few arguments did erupt. No injuries or arrests were reported.