St Peter’s Basilica has reopened for thousands of people to pay their final respects to Pope Francis for a second day, following a brief pause after keeping its doors open all night.

The 16th-century basilica, where Francis’s simple wooden coffin is placed on the main altar, was scheduled to close at midnight but remained open until 5.30am to allow in those who still wished to enter.

The Vatican said on Thursday that more than 60,000 people had viewed the late pontiff’s body since the basilica opened to the faithful on Wednesday morning.

The pope, the head of the world’s 1.4 billion Catholics, died at his home in Casa Santa Marta on Monday, aged 88, after a stroke and subsequent heart failure.

In interviews published on Thursday, the head of the pontiff’s medical team said​ Francis had died quickly without suffering, and there was nothing that doctors could have done to save his life​.

Sergio Alfieri, a physician at Rome’s Gemelli hospital,​ said he got a phone call at around 5.30am on Monday to come quickly to the Vatican.​ “I entered his rooms and he [Francis] had his eyes open,” the doctor told ​Italy’s Corriere della Sera newspaper, adding: “I tried to call his name, but he did not respond to me ... He was in a coma.”

“In that moment, I knew there was nothing more to do,” said Alfieri.​ The pope had been recovering from double pneumonia, which had kept him in hospital for five weeks. However, his recovery appeared to be going well. The day before he died, the pontiff had appeared in St Peter’s Square in an open-air popemobile to greet cheering crowds on Easter Sunday.

Alfieri​ said he last saw Francis on Saturday afternoon, and the pope “was very well”.

In a separate interview with La Repubblica news outlet, Alfieri said Francis had shared one final regret with him – not being fit enough to perform a foot washing ritual on the feet of prisoners last week. The pope used to conduct the symbolic act of service and humility to echo the story of Christ’s washing of his disciples’ feet.

“He regretted he could not wash the feet of the prisoners,” said the doctor. “‘This time I couldn’t do it’ was the last thing he said to me.”

His body was moved to the basilica on Wednesday, when thousands of people started queueing for hours under the hot spring sun in St Peter’s Square to pay their final respects to Francis, who will lie in state until Friday evening.

In keeping with his requests for simple funeral rites, Francis was dressed in his vestments, holding a rosary, with his open casket lined with red cloth.

Unlike those of most of his predecessors, his coffin, which is being watched over by two Swiss Guards, has not been raised on a platform. That was one of the rituals Francis shunned when he simplified rules for papal funerals last year.

His funeral mass will take place at St Peter’s Square on Saturday morning, an event that will be attended by a host of world leaders and royals, including the British prime minister, Keir Starmer, the US president, Donald Trump, and Prince William. He will then be buried at the Santa Maria Maggiore Basilica in Rome’s Esquilino neighbourhood, breaking with longstanding Vatican tradition.

Mourners in St Peter’s Square had erupted into a prolonged but sombre applause on Wednesday as Francis’s coffin was carried through it by pallbearers in a solemn procession involving dozens of cardinals and bishops, and watched over by Swiss Guards.

The bells of the basilica gently tolled as a choir chanted psalms and prayers in Latin, repeating the call to “pray for us”.

“It was the most profound moment,” said Cardinal Thomas Christopher Collins, the former archbishop of Toronto, who was among the procession. “But from the simple prayers to the incense, it was no different to a [funeral] ritual that any baptised person would have.”

Francesco Catini, who travelled to Rome from Venice, had waited for four hours to see Francis’s body. “It was a beautiful experience,” he said. “To me, Francis was a living example of peace, of love, and especially of humility and solidarity.”

Chiara Frassine, from Brescia in northern Italy, had waited a similar amount of time. “I’m very happy to be here,” she said as she left the basilica. “Pope Francis had a pure soul. He was a humble point of reference for many people, not just Catholics.”

Not everyone waiting to pay their respects was Catholic. Standing at the end of the queue was Gunnar Prieß, from Germany, who arrived in the Italian capital on Wednesday morning.

“I booked a flight only to be here to see this,” he said. “I am not Catholic, but this is so majestic. What we’re seeing here today is the expression of a holy ritual that goes back 2,000 years. There’s an aura in the Vatican and I wanted to experience it.”

As the funeral rituals continue, speculation is rife about who will succeed Francis. Some 103 cardinals met on Wednesday evening and approved nine days of mourning from the date of the funeral, with a conclave – the secret election process to choose a new pope – therefore not expected to begin before 5 May.

There is no clear frontrunner, although Luis Antonio Tagle, a reformer from the Philippines, and Pietro Parolin, from Italy, who were among the procession, are early favourites.

Collins will be involved in the conclave too and, at 78, will be among the 135 cardinals eligible to vote. But he declined to give any hint of who he thought might succeed Francis.

Reuters contributed to this report