Around 800 people gathered outside Prime Minister Theresa May's residence at Downing Street to protest against the United Kingdom government's handling of the disaster, said Joey Ayoub, a journalist and activist who joined others at Number 10.
"Sadly at this time, there are 58 people who we have been told were in Grenfell Tower on the night that are missing and therefore sadly I have to assume that they are dead", a police spokesman told reporters.
Sixteen bodies have now been recovered from Grenfell Tower and taken to a mortuary.
The refurbishment included the fitting of cladding that was "commonly used", according to the contractor responsible for the works, but which may have contributed to the fire spreading so quickly.
Alongside both police and fire investigations into the blaze, she has promised to set up a public inquiry, Reuters news agency reported.
Criticism of May intensified Friday after she sidestepped questions in a televised interview about whether she had underestimated the public's anger and frustration.
Opponents said May's handling of the fire has thrust her position further into doubt by showing a failure to feel the public mood and act decisively.
More than 3 million pounds ($3.8 million) has been raised for victims of the London high-rise fire that has killed at least 30 people and left dozens homeless.
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The officer said that the current information is based only on the number of people they believed were present inside the tower when it caught fire during the wee hours of Wednesday.
The group of residents and community leaders outside Number 10 on Saturday following a meeting with the PM.
The meeting is unlikely to quell complaints that May has been slow to reach out to fire survivors, despite her announcement of a $6.4 million emergency fund to help displaced families.
"Today is traditionally a day of celebration", the Queen said in a statement. "The country has witnessed a succession of awful tragedies".
"We've worked tirelessly to confirm the number of people who we believe were in the tower on the night and, at this time we can not assume they are safe and well", he said.
She said earlier that the national mood is somber but that Britain is resolute in the face of adversity.
The anger on the streets of London's North Kensington has been growing in the past 48 hours.
Police also identified the first known victim of the fire, 23-year-old Mohammed Al-Habjali, who lived in Grenfell Tower.
Some wore T-shirts with images of missing loved ones as they climbed the front steps and pushed their way into the building. She celebrates two birthdays each year: her actual birthday on 21 April and her official one which usually falls on the second Saturday in June. The protesters eventually made their way to busy Oxford Circus, where they staged a sit-in.