Staff Reporter :Bangladesh University of Engineering and Technology (BUET) was closed sine die after “attack and vandalism” on its academic buildings by the some unruly students.The university authorities in an emergency meeting instructed the students to leave residential halls by 5pm Thursday, said BUET student welfare Wing Chief Delwar Hossain. “The decision followed violence on the campus by students demanding postponement of the examinations. Authorities blamed a group of students who besieged the offices of BUET vice-chancellor, registrar and students’ welfare director on June 23 for chaos.BUET Registrar AKM Masud, said the students vandalised some academic buildings and set them on fire last night. That is why the authorities declared the university closed for indefinite period, he said. The protesters, mainly of 2009 batch, demanded the authorities to take the terminal examinations after Eid vacation instead of scheduled June 27, one of the students said.