Machete-wielding assailants hacked to death a village doctor and wounded a university teacher in Bangladesh on Friday in what police suspected is the latest in a series attacks by Islamic extremists in the majority-Muslim nation.

The attackers rode a motorcycle, which they used to block the victims' motorcycle in the western district of Kushtia, 150 miles (245 km) from Dhaka, district Police Chief Mohammad Sahabuddin Chowdhury said.

The homeopathic doctor, Mir Sanaur Rahman, 55, was killed on the spot, and his companion, identified as Saifuzzaman, 45, suffered serious wounds. Police found a bloody machete at the scene.

"We suspect Islamist militants are behind the attack," Chowdhury said.

Police were checking whether the victims had any particular enemies or if other factors could have been a motive, but media reported associates of the doctor saying he had a reputation for progressive views. Friends of the wounded university teacher said he too was known for being progressive-minded.

The doctor was on his way to a weekly free clinic he operated when he was attacked.

Over the past year, the South Asian nation of 160 million has seen a surge of attacks on atheist bloggers, academics, members of religious minorities and foreign aid workers.

At least 26 people have been killed since February 2015, including five secular bloggers, a publisher and two gay-rights campaigners.

Al Qaeda in the Indian Subcontinent has claimed some of he attacks. Members of the Islamic State group have also claimed responsibility for some attacks, including the killings of two foreigners last year and a university professor and a Hindu last month.

The government has denied that the Islamic State or al Qaeda terrorist groups have a presence in the country and says homegrown Islamic extremists are responsible.

Police have announced 1.8 million taka ($23,000) rewards for information leading to the arrest of six militants of a banned homegrown group called Ansarullah Bangla Team, which is believed to be behind the killing of the bloggers.