Services were partially down for more than four hours.
Seven others were also injured in the accident.
The accident took place on the Sheikh Mohamed bin Zayed Road.
Eight people died in the accident.
The two buses carried a total of 35 children.
Both accidents happened in the emirate of Ras Al Khaimah.
The explosion took place in the sixth floor of an apartment in the Al Ghurair Building in Mankhool.