Bangladesh health officials investigate after dozens lose consciousness

Bangladeshi health officials were investigating the cause of a mysterious illness that left dozens of students and teachers unconscious at a school near the capital, officials said Sunday.

Over the past week, at least 50 students and four teachers suffered headaches, nausea or convulsions before losing consciousness at Adiabad Islamia High School and College in Narsingdi district, about 30 kilometers (20 miles) east of Dhaka.

A team of health experts from a disease control center and the military visited the school over the weekend to investigate, principal Shakhawat Hossain said.

"They are checking the classrooms and the patients," Hossain said.

Public health official Birendranath Sinha said a virus, chemical or gas contamination, could be responsible. He did not elaborate.

About 20 students were taken to state-run Narsingdi Sadar Hospital and released after receiving first aid. Some 30 others were still being treated at other medical centers.

The school, which has nearly 1,200 students on a sprawling riverside campus, was closed for three days, local government administrator Jillar Rahman said.