Editor’s Note: Ravi Agrawal is CNN’s New Delhi Bureau chief. Follow him on Twitter: @RaviAgrawalCNN.

Story highlights

For more than two years, a spate of brutal murders has rocked the South Asian nation

ISIS has claimed a number of the attacks through its media affiliates -- Bangladesh rejects this

But a motive and payoff is clear: a foothold in a country with the world's fourth-largest Muslim population

New Delhi CNN  — 

Bangladesh has a number of things going for it: its economy is growing, it’s a democracy with a youthful population, and it’s blessed with fertile lands.

It is also home to almost 150 million Muslims, and up until recently steered clear of the kind of radicalism that has plagued other parts of the world. But unfortunately there are ominous signs that this is changing.

For more than two years, a spate of brutal murders has rocked the South Asian nation. At first the killings had a clear pattern, targeting well-known secular writers in the capital, Dhaka. The attacks seemed designed to silence those who dared to criticize Islam.

One of the most high-profile of these – the murder of the Bangladeshi-American writer Avijit Roy in 2014 – took place right outside Dhaka’s annual book fair.

Then in April this year, a well-known LGBT activist and his friend were murdered while they were at home.

In recent weeks these attacks extended into the countryside, increased in frequency, and targeted everyone from university professors to a seemingly random selection of Hindus, Christians, Buddhists, and even Sufi Muslims.