Police in Bangladesh have arrested more than 5,000 suspected militants after dozens of brutal killings of Christians, atheists and others, many hacked down by men on motorcycles using machetes and swords. More than 80 of those arrested are believed to be Islamic extremists.

The arrests have been made on suspicion of firearms, drugs and other offences. 

Every non-Muslim who takes to social media, the blogosphere or other media espousing a less-than-extremist view, as well as non-extremist Muslims as many in the Sunni community are, are now feared to be targets of the killers.

Killings this month alone include:

• Nitya Ranjan Pandey, 60, a Hindu monastery worker stabbed to death in Pabna just a few days ago.
• Hindu priest Ananta Gopal Ganguly, 70, whose throat was slit as he was on his way to temple in the Jhenaidah district, west of Dhaka.
• Christian grocery store owner Sunil Gomes, murdered in his shop after leaving morning prayers in his home in the village of Bonpara.
• In May, a Christian family's home in Baghadanga Girjapara was targeted with homemade bombs.
• In April, Islamic State claimed responsibility for the murder of Rezaul Karim Siddiquee, 58, a professor of English north-west Bangladesh who was hacked to death. 

Islamic State and Al Qaeda have claimd responsibility between them for most of the murders.

As the thousands of militants were arrested and 1,000 motorcycles seized, Bangladesh Prime Minister Sheikh Hasina pledged that all the murderers will be caught. She said: "It may take time, but God willing, we will be able to bring them under control. Where will the criminals hide? Each and every killer will be brought to book."

Those arrested include Shahjahan Robin, a suspect in the murder of the wife of an anti-terror officer, Mahmuda Begum. 

Some of those detained belong to organisations such as the banned Jamaatul Mujahideen Bangladesh, or the Jagrata Muslim Janata Bangladesh.