The average working hours of junior high school teachers in Japan were the longest among 48 countries and regions surveyed by the Organization for Economic Cooperation and Development, it said Wednesday.

Lower secondary teachers in Japan worked 56 hours per week on average, compared with an average of 38.3 hours a week among all of the participants of the "2018 Teaching and Learning International Survey."

It is the second time in a row that the OECD has found that Japanese teachers work the longest hours, up 2.1 hours from the previous survey in 2013.

Similarly, primary school teachers in Japan worked 54.4 hours a week, longer on average than their peers in 15 countries and economies surveyed.

The survey for Japan was conducted by the Paris-based institution from February to March 2018, with questionnaires sent to 3,568 junior high school teachers, 3,321 elementary school teachers and around 400 principals.

Japan's education ministry decided in January to cap overtime for teachers at 45 hours per month, or 360 hours over 12 months.

A junior high school teacher spent an average of 7.5 hours per week on students' extracurricular club activities, compared with the overall average of 1.9 hours a week, while administrative work took up 5.6 hours, compared with the total average of 2.7 hours.

Primary school teachers in Japan spent longer on planning, preparing lessons and paperwork than those in other countries. They devoted an average of 0.6 hour to extracurricular activities.

Japan's new curriculum guidelines promote deeper learning through independent and interactive means, but the percentage of secondary school teachers who frequently or always gave "tasks that require students to think critically" was 12.6 percent, the lowest figure and a far cry from the 61 percent average among all the countries surveyed.

Further, only 16.1 percent of teachers in Japan presented "tasks for which there is no obvious solution" compared with the 37.5 percent average among all the countries surveyed.