A primary school teacher who indecently assaulted three pupils aged 11 and 12 was sentenced to 6 months' jail at Tuen Mun Court yesterday. Wan Kwok-leung, 44, who worked at a school in Leung King Estate, Tuen Mun, for 15 years, assaulted the students on the pretext of taking pictures with them on five occasions in the past three years.