Iraq has detained or imprisoned at least 19,000 people accused of connections to the Daesh terrorist group or other terror-related offenses, and sentenced more than 3,000 of them to death, according to an analysis by The Associated Press.

The mass incarceration and speed of guilty verdicts raise concerns over potential miscarriages of justice — and worries that jailed militants are recruiting within the general prison population to build new extremist networks.

The AP count is based partially on an analysis of a spreadsheet listing all 27,849 people imprisoned in Iraq as of late January, provided by an official who requested anonymity because he was not authorized to speak to the media.

The AP determined that 8,861 of the prisoners listed in the spreadsheet were convicted of terrorism-related charges since the beginning of 2013 — arrests overwhelmingly likely to be linked to Daesh, according to an intelligence figure in Baghdad.

In addition, another 11,000 people currently are being detained by the intelligence branch of the Interior Ministry, undergoing interrogation or awaiting trial, a second intelligence official said. Both intelligence officials spoke on condition of anonymity because they were not authorized to brief the press.

"There's been great overcrowding ... Iraq needs a large number of investigators and judges to resolve this issue," Fadhel al-Gharwari, a member of Iraqi's parliament-appointed human rights commission, told the AP. Al-Gharwari said many legal proceedings have been delayed because the country lacks the resources to respond to the spike in incarcerations.

Large numbers of Iraqis were detained during the 2000s, when the U.S. and Iraqi governments were battling militants, including al-Qaida, and Shiite militias. In 2007, at the height of the fighting, the U.S. military held 25,000 detainees. The spreadsheet obtained by the AP showed that about 6,000 people arrested on terror charges before 2013 still are serving those sentences.

But the current wave of detentions has hit the Iraqi justice system much harder because past arrests were spread out over a much longer period and the largest numbers of detainees were held by the American military, with only a portion sent to Iraqi courts and the rest released.

Human Rights Watch warned in November that the broad use of terrorism laws meant those with minimal connections to Daesh are caught up in prosecutions alongside those behind the worst abuses. The group estimated a similar number of detainees and prisoners — about 20,000 in all.

"Based on all my meetings with senior government officials, I get the sense that no one — perhaps not even the prime minster himself — knows the full number of detainees," said Belkis Wille, the organization's senior Iraq researcher.

Prime Minister Haider al-Abadi, who is running to retain his position in national elections slated for May, has repeatedly called for accelerated death sentences for those charged with terrorism. The spreadsheet analyzed by the AP showed that 3,130 prisoners have been sentenced to death on terrorism charges since 2013.

Since 2014, about 250 executions of convicted Daesh members have been carried out, according to the Baghdad-based intelligence official. About 100 of those took place last year, a sign of the accelerating pace of hangings.