Within six days of announcing a crackdown on Islamist militants, Bangladesh had filled its jailhouses with 11,600 new detainees in what seemed like an astonishing display of law enforcement might. The problem is, less than 2 percent of those picked up are suspected radicals, and not one is considered to be a high-level operative.

The rest? Most are accused of petty crimes such as theft, burglary or small-time drug smuggling. At least 2,000 are members of the main opposition party, according to its spokesman, while others were believed to belong to a key ally of that party.

Analysts, rights groups and opponents of Prime Minister Sheikh Hasina's secular government now question the crackdown. Was it truly an effort to stop a series of brazen, deadly attacks by Muslim extremists on various minorities, or an attempt to gain political advantage from the fear the killings have generated at home and abroad?

Lisa Curtis, an expert on South Asia at the Heritage Foundation think tank in Washington, D.C., said a crackdown on extremists was needed. But given that only 177 of the thousands detained are actually suspected of radical militancy, according to police, she said that the dragnet will begin to look more like a tool to pressure the political opposition rather than a serious effort to stop the attacks.

The law enforcement campaign could actually deepen the divide between the secular government's supporters and those longing for Islamic rule, possibly even encouraging militants, analysts said.

"The current political deadlock in the country is opening the door for Islamist extremists to gain more recruits and influence, and will make it difficult for the Bangladeshi government to build a national consensus against the extremists," Curtis said.

Bangladesh, in addressing the criticism over the crackdown, pledged to refocus its security efforts against suspected militants blamed for the killings of nearly two dozen atheist writers, publishers, religious minorities, social activists and foreign aid workers since 2013. Many of those deaths have occurred in recent months.

The so-called "machete attacks" have terrified the country's minorities and triggered alarm in the United States and Europe, where some governments have begun offering asylum to those at risk. In most of the killings, a group of young men cut their victims down with meat cleavers and machetes before fleeing the scene.

While most of the attacks have been claimed by either the Islamic State or groups affiliated with al-Qaida, the government denies the presence of either transnational jihadi group in Bangladesh.

Instead, Hasina's government accuses local terrorists and Islamist political parties — especially the main opposition Bangladesh Nationalist Party and its ally Jamaat-e-Islami — of orchestrating the violence in order to destabilize the nation. The two parties deny any involvement.

Hasina announced the crackdown last week, after the wife of a police superintendent was shot and stabbed to death. The victim had been an ardent campaigner against militants, and many within the country's establishment were stunned by the attack on someone they had considered as one of their own.

Yet police now say the crackdown was never meant to target only radicals, but was also aimed at arresting people accused of trading in narcotics and firearms. While that "special drive" was carried out in tandem with the anti-militancy campaign, it was never communicated to the media until it was over, police spokesman Kamrul Ahsan said.

Human Rights Watch said in a statement Friday that while Bangladesh should be stepping up its anti-militancy efforts, it "should immediately stop arbitrarily arresting people without proper evidence of crime" and release those who are not charged.

The group's Asia director, Brad Adams, accused the government of trying to make up for "a slow and complacent response" to the militant attacks by "falling back on old habits of rounding up the 'usual suspects' instead of doing the hard work of carrying out proper investigations."

Most of the detainees were still in custody on Friday, with their families and friends crowding into police stations, court houses and jails in an effort to pay bail or in some other way secure their loved ones' release. According to local media, that has included bribing the police.

Those rounded up this week included two suspects who, under questioning, revealed the identity of a man wanted in an October attack against a publisher, police said Thursday. That suspect, they said, could help authorities apprehend more suspects wanted for the separate killing of another publisher on the same day.

Still, most attack suspects remain at large. Authorities have yet to explain why the investigations have been so difficult even as they insist they know who is behind them.

The U.S. State Department's South and Central Asia bureau this week repeated its support for helping Bangladesh root out Islamist militancy, while also advising transparency in its investigations and "respect for fair trials and other protections envisioned by domestic and international law."

Analysts suggested the crackdown was also likely aimed at placating international concerns about security in the country.

"For a long time, Bangladeshi officials have tended to lump together political opponents and criminal adversaries. We may be seeing some recognition that a more professional approach is needed," said Jonah Blank, senior political scientist and expert on South Asia at Rand Corp. in Washington, D.C.

A former police chief who served when the opposition was in power suggested the crackdown was designed to cover up the deterioration of law and order.

"Police wanted to show the countrymen and the international community that they have engaged all its strength to arrest the killers and stop the attacks," said Nur Mohammad, who served three years as the police inspector general from 2007, when a caretaker government was in office.

"Usually, such drives are launched without any groundwork and thus large number of innocent people are nabbed and harassed," he said.

BNP officials say Hasina is blaming them for the attacks to divert attention from her loss of control over security. It also accuses her of cracking down on political opponents to prevent challenges to her mandate. Hasina's Awami League party easily won the 2014 elections, which opposition parties boycotted, alleging unfair conditions.

"Hasina is playing a dangerous game," said BNP's London-based spokesman Humaiun Kobir. "She is using the crackdown to kill off democratic opposition," and could end up clearing the way for militants to mount their own political challenge.

"We think extremists are now trying to come in on the back of democracy," sensing an opportunity among critics who feel the country isn't working, Kobir said.

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Associated Press writer Matthew Pennington in Washington, D.C. contributed to this report.

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