Two paramedics sat up in bed in the intensive care unit of the Ottawa Hospital on Thursday, one day after a training exercise explosion in Kanata left them with second-degree burns on their hands and legs.

Supt. Craig MacInnes and Reid Purdy were sedated after the explosion on Wednesday morning and intubated to prevent their airways from swelling shut. Ottawa paramedic chief Anthony Di Monte said both were alert when he met with them on Thursday morning but the tubes remained in their throats.

Reid Purdy and Craig MacInnes paramedics injured explosion June 18 2014

Ottawa paramedics Reid Purdy, left, and Supt. Craig MacInnes, right, were seriously injured in an explosion during a training exercise in Kanata on Wednesday morning. (Facebook/CBC)

"We were able to kind of exchange and make grunts and talk in that way. It's very, very positive," Di Monte said. "I'm pleased to report that they are progressing very positively. I want to couch that they're still in the intensive care unit. They're still in serious condition."

He said the families of the injured men want to thank the public for an "outpouring of support."

A third paramedic and two Ottawa police officers sustained minor injuries in the explosion. All were wearing protective gear during the training exercise, Di Monte said.

SIU, Ontario Ministry of Labour investigating

Ottawa police, paramedics and RCMP had been conducting a joint forced-entry exercise involving explosives at an abandoned house on March Road on Wednesday morning. The hostage simulation involved officers inside the house acting as victims and suspects, police sources told CBC News.

Di Monte said "doors were being broken down" after the explosion to support those who were injured.

"When the chips are down you can certainly depend on those members to be there for you," he said.

Sources told CBC News that explosive devices are "triple checked" before use, and that all officers are supposed to take cover before explosions.

Ottawa police chief Charles Bordeleau said Wednesday that he could not get into specifics about the training exercise or the types of explosives used because the Special Investigations Unit had invoked its mandate. The SIU investigates incidents in which police officers are involved in serious injuries or death. 

Ontario's Ministry of Labour is also investigating.