by Chief Minister Kristina Moore told the BBC “we have now moved into a recovery operation”.
It is understood there were nine known residents in the block before the blast in St Helier on Saturday morning.
Three bodies have been found at the Pier Road scene and specialist teams are continuing to look for six more.
The final total is estimated to be up to a dozen, as details on visitors to the flats are unknown.
Specialist teams and a search dog are on the scene, following the collapse.
Chief of Jersey Police Robin Smith said: “It is with sadness that I am confirming that the search and rescue operation has been moved to a recovery operation.
“The decision was made after a detailed assessment and following the use of specialist K9 units.
“Disaster victim identification strategies are in place and specialist officers are surveying the scene with fire and ambulance services and tactical advisers from urban search and rescue.”
Ms Moore told the BBC she was woken by the blast.
“Across the island you could hear this extraordinary sound,” she said.
“It was not quite clear what it was but it certainly woke myself and many people.
“It’s unthinkable news, we’re all absolutely devastated and really concerned for the people who are involved, for those whose lives have been lost.
“Those families will get the answers they need,” she said.
“We’re so grateful to the emergency services and everybody who is absolutely committed to searching through the rubble to find everybody.”
Specialist teams from the UK’s Ministry of Defence and fire services have been supporting local crews.
They include the South West Hazardous Area Response Team, alongside an Urban Search and Rescue Team from Hampshire & Isle of Wight Fire & Rescue Service.
BBC Radio Jersey reporter Meghan Owen said smoke was still rising from the scene on Sunday morning.
“Search and rescue teams are working under floodlights in the bitter cold,” she said.
“They are being particularly careful because the rubble is unstable.”
Chief fire officer Paul Brown earlier told a press conference: “The primary challenge is the fact that we have a dangerous structure that has collapsed.”
Two people who were in hospital earlier have been released and one other person is receiving treatment.
The blast happened at about 04:00 GMT on Saturday.
Police chief Mr Smith said “there are a number of working hypotheses” as to what had happened but warned people “not to speculate”.
He added: “Thankfully these circumstances are very rare but nevertheless they are of deep concern to communities.”
Jersey’s gas supplier, Island Energy, said it was working with the fire service to understand what had happened.
It was earlier confirmed the fire service had attended the scene on Friday night after the smell of gas was reported.
The chief fire officer was asked if the call on Friday had had anything to do with the cause of the explosion.
Mr Brown said: “I will give you an answer to that but what I’d like to do for the moment is focus on the emergency response, talk to my colleagues and consider those bits that are subject to investigation and make sure I don’t tell you something that I need to tell someone else first.”
Ms Moore said “all the facts will have to be gathered” and there would be a “full investigation”.
The three-storey building which collapsed is owned by Andium Homes which is a state-owned but independent company that rents out properties.
It said it was focusing on supporting residents at the estate.
Ms Moore said residents displaced by the blast were being found somewhere to stay.
“This is going to take some days and we will keep everyone updated and fully informed, and we will do our very best to ensure everybody is properly looked after,” she added.
The Town Church opened on Saturday evening for islanders to light candles and pay respects to those who had died.
Justice Secretary and Deputy Prime Minister Dominic Raab tweeted he was “deeply saddened” by the news.
“I commend the work of the emergency services responding and we stand ready to support in any way we can,” he said.
The incident comes days after three fishermen were reported missing following a collision at sea on Thursday.
Ms Moore said: “It’s been a really tough week, it’s just been unprecedented.
“Two very different tragedies, but I think it showed the resilience we have and the amazing emergency response that we have been able to muster, but also the companionship of our near neighbours who have joined in our efforts and we’re really grateful to them.”
