Four bombs ripped through minibuses and a mosque in Afghanistan on Wednesday, killing at least 12 people, officials said.

The number of bomb attacks have dropped across the country since the Taliban seized power last year in August, but several deadly bombings had rocked the country during the holy month of Ramadan.

On Wednesday, at least 10 people were killed when three bombs placed on board separate minibuses exploded in the northern city of Mazar-i-Sharif, a health official and 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.

Najibullah Tawana, head of Balkh health department, said three women were among the 10 killed in the blasts on board the vehicles.

Another bomb exploded inside a mosque in the capital Kabul late on Wednesday, killing at least two people and wounding 10 others, the interior ministry said.

Kabul's Emergency hospital tweeted that five people had been killed in the mosque blast and 22 others wounded.

Several ambulances rushed to the mosque in Kabul to ferry the victims of the blast, witnesses 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.

It was still unclear whether Wednesday's bombings targeted any specific community.

Dozens of civilians were killed in Kabul and other cities during Ramadan that ended on April 30 in Afghanistan in the primarily sectarian attacks -- some claimed by the so-called Islamic State group.

On April 29, at least 10 people were killed in a Sunni mosque in Kabul in an attack that appeared to have targeted members of the minority Sufi community who were performing rituals.

On April 21, a bomb at a Shiite mosque in Mazar-i-Sharif had killed at least 12 worshippers and wounded scores more.

The deadliest attack during Ramadan was in the northern city of Kunduz when a bomb tore through a mosque also targeting Sufi worshippers on April 22.

At least 33 people were killed in that blast and scores more were wounded.

The regional branch of IS in Sunni-majority Afghanistan has repeatedly targeted Shiites and minorities such as Sufis, who follow a mystical branch of Islam.

IS is a Sunni Islamist group, like the Taliban, but the two are bitter rivals.

The biggest ideological difference is that the Taliban pursued an Afghanistan free of foreign forces, whereas IS wants an Islamic caliphate stretching from Turkey to Pakistan and beyond.

Taliban officials insist their forces have defeated IS, but analysts say the jihadist group remains a key security challenge.