HERAT, AFGHANISTAN - A roadside bomb in western Afghanistan killed at least 35 people traveling on a bus, including children, and injured 27 others, officials said on Wednesday.

Security has been deteriorating across Afghanistan, with the Taliban and Islamic State fighters mounting near-daily attacks on Afghan forces, government employees and civilians.

The blast on the highway linking the provincial capitals of Herat and Kandahar occurred in the Ab Khorma area of Farah province, said provincial police spokesman Mohibullah Mohib.

"The bomb was freshly planted by the Taliban insurgents to target Afghan and foreign security forces," he said, adding most of the dead or injured were women and children.

A Taliban official said their fighters were not responsible for planting landmines in the area.

"The blast has not been conducted by the Taliban, we are investigating the incident," said spokesman Zabihullah Mujahid.

So far, no militant group has claimed responsibility for the attack.

Government and aid officials say the numbers of those being killed and maimed is rising because of new explosives planted by the Taliban, who now control more territory than at any point since their ouster nearly 18 years ago.

According to the United Nations Mine Action Service, more than 1,415 Afghan civilians were killed or injured by landmines and explosive remnants of war last year. In eastern Nangarhar province, clashes between the Taliban and Afghan forces on Wednesday caused civilian casualties.

Sohrab Qaderi, a provincial council member of Nangarhar, said Afghan special forces conducted operations in the Gandumak area which is under Taliban control.

"Two Taliban fighters and five civilians were killed," said Qaderi.

Afghan and foreign forces said civilians are hurt or killed during ground raids or air strikes as insurgents use them as human shields. -Reuters