Dhaka, Nov. 1 -- The numbers told a story that few in Bangladesh's education system wanted to see. After years of disruption, the Higher Secondary Certificate examination has delivered its worst results in more than two decades, exposing weaknesses that officials say can no longer be ignored.

Only 52.12 percent of candidates passed this year's HSC and equivalent examinations, the lowest rate since 2004.

The result has left education officials both disappointed and surprised, while reigniting questions about what students are learning, how they are being taught and whether their examination scripts are being marked consistently.

Of the students who passed, 40,084 secured GPA-5, accounting for 6.2 percent of successful candidates. Last y...