Mounted police and other officers are at the scene of the protests, with some entering the town hall.
Police broke up a scuffle between members of the crowd as the Mrs May's vehicle drove off. The Guardian newspaper reported Friday that contractors installed a cheaper, less flame-resistant type of panelling on the building in the renovation that was completed in May 2016.
Ms May today announced a $NZ8.8 million fund following meeting with survivors of the Grenfell Tower tragedy. But May was expected to visit survivors later Friday.
Mrs May spent nearly an hour speaking to patients and staff at London's Chelsea and Westminster Hospital, a day after visiting the scene of the blaze in west London to talk to firefighters, police and other emergency workers.
"It really devastated me", he said.
"At this moment in time, the fire is still ongoing, so it is not safe to take people out of the tower", she told reporters.
"They have been left with nothing - no bank cards, no money, no means of caring for their children or relatives", the prime minister said in a statement Friday.
But he told Morning Report after a disaster of the scale of the London fire "you have to kick the tyres and re-check".
Lord Porter, chairman of the Local Government Association, said: "Fire risk assessments and the construction of buildings are being reviewed and double checks are being made to ensure remedial work recommended under previous assessments have been carried out".
Mrs May's visits followed one by the Queen and the Duke of Cambridge, who met volunteers and those who had lost everything.
The death toll is expected to rise further as rescue workers continue to search for victims - an operation that Metropolitan Police Commander Stuart Cundy described as "extremely challenging".
At least 30 people have been killed in a massive blaze that engulfed a London high-rise in a tragedy that has deeply shocked Britain.
"What we are doing is putting in place the support that will help them".
British Prime Minister Theresa May has ordered a full public inquiry into the fire while police have subsequently launched a criminal investigation.
But Mrs Leadsom, who visited the area in her role as Leader of the Commons, rejected Mr Portillo's criticisms, insisting that Mrs May was "absolutely heartbroken" by the blaze and was simply trying to make sure the Government did everything it could to deal with its aftermath.
British health authorities say they are still treating 19 patients, 10 of whom remain in critical condition after the London high-rise fire.
The investigation into the cause of the fire that has now been extinguished will take weeks, he added.
Anger swelled, meanwhile, as survivors and others pressed for answers on whether inadequate safety systems or substandard construction material could have contributed to a blaze that climbed up the building faster than people could flee. Everyone - not just my family, every single person in there. "The fire started on the upper floors".
In an unannounced tour of the area, the Queen, 91, and her grandson, 34, went to the Westway Sports Centre close to the tower where authorities now say 30 people died in Wednesday's fire.