Company executives from Soma Komur Isletmeleri AS were among the 25 people detained by Turkish people in the wake of the mining disaster that left 301 workers dead from an underground coal mine fire.

The Wall Street Journal reported that a Turkish court granted requests for the three arrests and two suspects were released. Four people were released and the others were still being questioned as of May 18, six days after the deadly fire began.

"The suspects are accused of negligent acts causing multiple deaths and injuries," Bekir Sahiner, a chief prosecutor in the region, said late Sunday in a televised briefing from Soma. "The investigation is proceeding in a speedy manner."

The judiciary's move comes as Prime Minister Recep Tayyip Erdogan's government is drawing fire over its handling of the disaster, which spotlighted weaknesses in workplace safety and has triggered criticism for a failure to identify what caused the deadly fire in the mine. The chief prosecutor said an investigation showed that a power-unit explosion inside the mine didn't cause the fire, as the government initially had claimed. Early findings indicate spontaneous combustion of coal could be behind the catastrophe, Mr. Sahiner said.

After sporadic protests across the nation to show solidarity with the miners, and widely criticized police intervention against mourners, the detentions signaled an effort to temper mounting public anger, opposition lawmakers and analysts said.

The prosecutors' push could also place blame for the catastrophe, helping alleviate the fallout from Erdogan's comments on Wednesday that accidents are a natural part of mining, and anger over footage showing the premier's adviser kicking a protester.

Authorities have reacted to public anger by repeatedly promising a thorough investigation, pledging to bring any culprits to justice and saying the probe won't turn into a coverup.

"Regardless of who it is, those responsible will get the punishment they deserve," Deputy Prime Minister Emrullah Isler said in a message posted Sunday on his official Twitter account. "All necessary steps will be taken and all precautions will be put in place so that we never again live through such grief."

The initial round of arrests come after police faced off with protesters in Istanbul and the capital, Ankara, while the Aegean city of Izmir just south of Soma has seen multiple marches.