A Hindu college teacher was seriously injured on Wednesday when he was assaulted by suspected Islamists, police said, the latest in a string of attacks on minority members and liberal activists in the mainly Muslim nation.

The attack came amid a week-long crackdown on Islamists begun on Friday, as Prime Minister Sheikh Hasina vowed to halt a wave of targeted killings, in which more than 11,000 people have been arrested.

Ripon Chakraborty, a mathematics teacher, was attacked by three knife-wielding assailants on Wednesday when he opened the door at his home in Madaripur, 70 km of the capital, Dhaka, police said.

"The 50-year-old teacher was hacked in his head and neck as he opened the door," police officer Ziaul Murshed said.

Police are questioning one of the attackers who was caught by local people as he fled, he added.

Militants have killed more than 30 people in Bangladesh since early last year. Among those targeted were atheist bloggers, liberal academics, gay rights campaigners, foreign aid workers, members of minority Muslim sects and other religious groups.

Islamic State or al Qaeda has claimed responsibility for most of the killings, but the government denies either group has a presence in Bangladesh. Police say home-grown militants from Jamaat-ul-Mujahideen and Ansarullah Bangla Team are responsible.

In the past week alone, an elderly Hindu priest, a Hindu monastery worker and a Christian shopkeeper were hacked to death, and the Muslim wife of a counter-terrorism police official was also killed

Hindus make up about 9 percent of Bangladesh's 160 million population.

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