A suicide attack on a school bus in southwestern Pakistan killed three students of a military-run school on Wednesday, officials said, in the latest attack that underscores the deteriorating security situation in the region.

Boston Public Schools will require additional safety-related reports from its school bus contractor Transdev and the company is speeding up refresher training for its drivers, in the wake of a school bus crash in Hyde Park that killed a 5-year-old last month, Mayor Michelle Wu and Superintendent Mary Skipper announced early Friday morning.