Three bombs tore through minibuses in Afghanistan's northern city of Mazar-i-Sharif on Wednesday, killing at least nine people, police said.
"The bombs were placed on three minibuses in different districts of the city," Balkh provincial police spokesman Asif Waziri told AFP, adding that 15 other people were wounded.
Another bomb exploded inside a mosque in the capital Kabul late on Wednesday, killing at least two people and wounding 10 others, the Taliban interior ministry said.
The ministry said the bomb was placed inside a fan in the mosque.
No group has so far claimed the four bomb attacks on Wednesday.
The number of bomb attacks have dropped across the country since the Taliban seized power last August, but several cities were rocked by bombings during the holy month of Ramadan.
Dozens of civilians were killed in Ramadan in the primarily sectarian attacks – some claimed by the so-called Islamic State group.