DHAKA, Bangladesh - An unidentified young man stabbed a prominent teacher, writer and promoter of secular values at a university in a northeastern city in Bangladesh on Saturday, police said.

Local police official Shafiqul Islam said the attacker stood behind Zafar Iqbal and started stabbing him in the head during a seminar at a public university campus in Sylhet where he teaches electronic and electrical engineering.

Iqbal was flown to a military hospital in Dhaka. He will survive despite massive bleeding, according to doctors.

The motive behind the attack was not immediately clear.

The attacker, a bearded man who appears to be in his mid-20s, was caught by Iqbal's colleagues, students and police at the scene. He was also injured when some in the crowd began to beat him. Police said they were trying to determine his identity.

Prime Minister Sheikh Hasina condemned the attack. Activists in Dhaka and other cities and towns carried out processions to protest it.

Iqbal, considered a top-selling author and celebrity speaker, has been threatened by radical Islamists in the past. He is popular among young people for his public speeches and books that promote logic and secular values.

Bangladesh, a South Asian Muslim-majority nation of 160 million, is ruled by mostly secular laws based on British common law.

Iqbal is a champion of free speech and secularism in Bangladesh, which has experienced a rise in Islamic militancy in recent years.

Saturday's attack came after months of calm, though it was not clear if the assault was related to any radical groups.

Suspected Islamist extremists have carried out a series of attacks on secular and atheist writers, bloggers, foreigners and members of minority groups in the last four years, killing dozens.

Authorities blamed some domestic groups despite claims by the Islamic State group that they carried out some attacks. But the government rejected the claims by the Islamic State and said the group had no existence in the country. It says domestic groups such as Ansarullah Bangla Team, also known as Ansar al Islam, and Jumatul Mujahedeen Bangladesh were responsible for the attacks.

The government said the groups were weakened because of a crackdown in which about 60 suspects, including some commanders, were killed in raids across the country.

News from © The Associated Press, 2018