LONDON — Anger about the government’s handling of Britain’s worst building fire in decades surged Friday, as Londoners heckled Prime Minister Theresa May and stormed the headquarters of a local council to protest what they saw as a slow and inadequate response.

May, whose Conservative Party lost its majority in Parliament last week, is facing one of the biggest crises of her tenure, as Britons have raised questions about safety procedures and construction safety after a fire that ripped through a 24-story apartment tower in West London.

The official death toll rose to 30 on Friday, but authorities said it could easily reach 70. They also made a grim admission: A full accounting might be impossible because some victims may never be identified.

Queen Elizabeth II and her grandson Prince William visited a sports center Friday that had been turned into a place of grieving and support for victims of the fire and their families.

May, who had been criticized for meeting with rescue workers but not with victims, returned to the area where the fire took place, and announced a government fund to pay for emergency supplies, food, clothes, and other costs.

The fire left the building, Grenfell Tower, a charred ruin, and has left hundreds of people homeless. May, who also visited survivors of the fire at Chelsea and Westminster Hospital, said in a statement that she was horrified by their plight — her most emotional statement on the fire to date.

“I spoke with people who ran from the fire in only the clothes they were wearing,’’ May said. “They have been left with nothing — no bank cards, no money, no means of caring for their children or relatives. One woman told me she had escaped in only her top and underwear.’’

A former home secretary, responsible for policing and domestic security, May added: “Everyone affected by this tragedy needs reassurance that the government is there for them at this terrible time — and that is what I am determined to provide.’’

Not everyone was mollified by the announcement. Outside St. Clement’s Church, where May made her announcement, angry residents shouted “Coward!’’ and heckled May.

Nearby, dozens of angry residents entered the Town Hall of the Royal Borough of Kensington and Chelsea, which owns Grenfell Tower, to request a meeting with officials and to present a list of demands.

The demonstration was not violent, but it was loud and tense, with many protesters shouting “Not 17,’’ a reference to an earlier death toll that everyone agrees is far too low.

The demands included the relocation of dislocated residents within the borough, which is one of the most affluent in London but also contains extensive areas of housing for people of modest means; the immediate release of financial aid for victims and their families who have lost their belongings; and a complete roster — or at least the number — of the residents in the tower.

“Sadly, we may not be able to identify everybody,’’ said Stuart Cundy, a Metropolitan Police commander, who expressed his hope that the death toll would not climb above 100.