London police said on Tuesday that they were not treating an incident of a man crashing a car into a building and then attacking people and police with a sword as terrorism-related. 

He was arrested soon after. 

A 14-year-old boy wounded in the attack later succumbed to his injuries in hospital, police said a few hours after the attack.

The London Ambulance Service said paramedics treated five people and took them to hospital.

"This must have been a terrifying incident for those concerned," Deputy Assistant Commissioner Ade Adelekan said. He said he knew the community would want more information and that police would provide it as soon as possible. 

In the shorter term, he indicated investigators believed the danger to have passed.

"We are not looking for more suspects. This incident does not appear to be terror-related," he said. 

Local politicians hail police response, warn against speculation

Local MP Wes Streeting was among officials the first to raise the alarm online, saying that a critical incident had been declared in part of his constituency in East London. He noted subway station and road closures in response. 

Streeting later issued a statement thanking law enforcement and "particularly the heroic Metropolitan Police Officers who put themselves in harm's way to protect others." 

"They are the best of us," Streeting said. 

London Mayor Sadiq Khan, meanwhile, said he remained in "constant contact with the [police] commissioner." 

Khan also thanked law enforcement for "running towards danger to protect others." 

He urged people "not to speculate until the details of this incident are confirmed by police and not to post footage on social media." 

Hainault is a large suburban housing estate in Ilford in the Redbridge borough of East London. It's home to around 13,000 people, according to census data from 2011. 

 msh/wd (AP, Reuters)