New York, Jun 17 (IANS): The Bangladeshi authorities should investigate attacks on secular writers and others but must stop arbitrarily arresting people without proper evidence of a crime, Human Rights Watch said on Friday.

Between June 10 and 16, security forces have reportedly arrested over 11,000 people in connection with a spate of murders of bloggers with secular or atheist leanings, non-Muslims, members of the LGBT community and other progressive or liberal thinkers.

Those detained should either be charged on the basis of credible evidence of criminal activities and brought immediately before a judge, or be immediately released, Human Rights Watch said.

“After a slow and complacent response to these horrific attacks, Bangladesh’s security forces are falling back on old habits and rounding up the ‘usual suspects’ instead of doing the hard work of carrying out proper investigations,” the rights body said.

“The government has an obligation to put an end to these murders and hold the perpetrators to account, but it must do so through proper procedures set out in its own criminal code as well as in international law.”

The wave of targeted killings of bloggers, secularists, and religious minorities began in 2013 and has escalated in recent months.

To date, more than 50 have been killed, often through machete attacks in public spaces.

Many of these killings have subsequently been claimed by Daesh (ISIS) or Ansar al-Islam, a Bangladeshi militant group linked to Al Qaeda, but their involvement has not been established.

The government denies the presence of both groups in the country.