A total of 159 people are now unaccounted for - and at least four people have been killed - following the collapse of an apartment building in Florida.

Three more bodies were pulled from the rubble during what Miami-Dade mayor Daniella Levine Cava described as a "tragic night".

Ms Levine Cava said "we still have hope that we will find people alive", as rescue workers said sounds had been heard through the night at Champlain Towers South in the town of Surfside.

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Moment apartment block collapses in Miami Beach

"We are listening for sounds, human sounds and tapping," said fire chief Ray Jadallah.

A huge section of the 12-storey oceanfront building was reduced to rubble when it crashed to the ground around 1.30am local time on Thursday (6.30am UK time).

Image: Rescuers worked through the night and said sounds could be heard from the debris

Officials do not know how many were inside the 40-year-old residential high-rise when it collapsed - the cause of which is still unknown and being investigated.

Among those believed to be missing is a British mother and her child - and relatives of Paraguay's first lady.

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A relative of Bhavna Patel, a 38-year-old British and US citizen, confirmed to Sky News that she, her 42-year-old husband Vishal Patel and their one-year-old daughter Aishani Patel are yet to be found.

Image: British citizen Bhavna Patel and her family are among the missing

Kevin Spiegel, whose wife Judy is among the missing, told Sky's US correspondent Martha Kelner at the scene: "I slept there Sunday night, had to go to California to work in Watsonville, only to wake up in the middle of the night to hear this horrific news."

Joined by his two sons Michael and Josh, he added: "The situation behind us is actually getting worse by the day because of the smoke and little fires that are breaking out... it is not a good condition, even if there are air pockets - it's very concerning to myself and my family."

Image: Judy Spiegel's family are praying she will be found alive

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'Difficult times are coming' - Husband of woman missing after collapse

Fighting back tears, the couple's son Josh, a surgeon, said: "It's a struggle, we are praying every minute. We are hopeful that she's there, alive, and we are going to see her soon and be able to hold her hand and kiss her."

He added: "We understand that this is going to be an extremely long process and this excavation may take weeks, if not longer, and we are going to be here fighting every second."

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Friend's anguish over missing Miami Briton

Paraguayan foreign minister Euclides Acevedo told local media that six people from the South American country were still unaccounted for.

They are Sophia Lopez Moreira, the sister of first lady Silvana Abdo, her husband Luis Pettengill, her three children and the family's assistant, according to Paraguayan authorities.

Florida Senator Marco Rubio tweeted that almost a third of the missing are foreign nationals.

Image: Before and after images show how a huge part of the residential building has now been reduced to pile and bricks and concrete

President Joe Biden has approved an emergency declaration and ordered federal assistance to boost local efforts, as emergency crews remain on scene, including 130 firefighters.

Search teams have detected banging and other noises coming from the debris, but no voices.

At least 35 people have been pulled from the rubble, including a mother and child.

Built in 1981, the tower block comprised more than 130 flats, about 80 of which were occupied.

Video from nearby appeared to show the centre of the building collapsing first, with a section nearest the ocean teetering and coming down seconds later amid a huge dust cloud.