Bangladesh should hold an independent probe into a police crackdown on Islamist protests in which dozens died earlier this week to prevent future "bloodbaths", a global human rights body urged Saturday.
There are varying death tolls but an AFP tally from police and medical sources shows 38 people were killed Sunday and Monday when police sought to end protests by tens of thousands of Islamists in Dhaka and other locations.
"Without an independent investigation, accountability and improved policing methods, we could see serial bloodbaths" in Bangladesh," Brad Adams, Asia director of New York-based Human Rights Watch, warned.
The Islamists are trying to pressure the government into introducing a new anti-blasphemy law and have been calling for the execution of bloggers whom they accuse of having insulted the Prophet Mohammed.
Adams also criticised Hefajat-e-Islam or Protectorate of Islam, the hardline Islamic group behind the protest, for recruiting boys from seminaries to take part in the demonstrations.
They "were terrified by the experience of seeing dead bodies and large-scale violence", Adams said in a statement, adding: "Putting children in harm's way is extremely irresponsible."
London-based rights group Amnesty International also called for "an independent and impartial investigation into police use of force" this week, saying its own probe found at least 44 people were killed.
Prominent local daily Prothom Alo put the death toll at 49 including seven security officials.
Dhaka police said they used non-lethal weapons during the crackdown and "recovered 11 bodies after day-long clashes". But images on social media websites have fuelled speculation the toll is far higher than publicly acknowledged.
The main opposition Bangladesh Nationalist Party (BNP) says the death toll runs into "hundreds" and accuses authorities of concealing bodies, but has given no proof. The government insists the claims are "baseless".
The protest by Hefajat, which draws support from Islamic schools, is another sign of the divide between Islamists and the secular government after the deaths of around 100 people earlier this year in violence linked to war crimes trials.
The government is trying Islamist and other opposition leaders for crimes including genocide and rape that they allegedly committed during the country's 1971 war of independence against Pakistan.