(AP) - The Latest on an incident at a subway station in London (all times local):

9:10 p.m.

London police say they are making "good progress" in the investigation into the subway bombing.

Assistant Commissioner Mark Rowley said Friday night that the public should be reassured and that more police and troops will be on the streets.

He says "we are only aware of one device," referring to the bomb that partially detonated Friday morning on a subway train at the Parsons Green station in southwest London.

Rowley says "we have remnants of that device. We are chasing down suspects." He refused to provide further details about the bomb, saying an investigation is underway.

Rowley said police are combing through closed circuit TV film and other data seeking information on the suspected bomber and on possible accomplices.

___

8:50 p.m.

British officials have raised the country's terrorism threat level to "critical' - meaning another attack is expected shortly.

Prime Minister Theresa May acted on the recommendation of the Joint Terrorism Analysis Center after the subway train bombing attack Friday at the Parsons Green station in southwest London. The analysis includes security services, police and government agencies.

The threat was raised from "severe" to "critical" - its highest possible level.

A manhunt is under way after the improvised explosive device was detonated on a crowded subway car, injuring at least 29 people.

May said military troops would augment the police presence in a "proportionate and sensible step."

    
__
    
8:35 p.m.
    
The Islamic State group is claiming that the London subway explosion was carried out by an affiliated unit.
    
The claim was posted Friday on channels affiliated with the extremist group.
    
A homemade bomb planted in a rush-hour subway car injured 29 people in London on Friday. It has sparked a huge manhunt for the perpetrators of what police said was the fourth terrorist attack in the British capital this year.
    
___
    
6:15 p.m.
    
British authorities say the number of people treated at hospitals after the bombing on the London Underground subway has risen to 29.
    
The National Health Service says 21 people are being treated and eight others have already been discharged. The London Ambulance Service says it took 19 patients to hospitals, most with minor injuries. The others went in themselves.
    
Police say most of those injured by an improvised explosive device on Friday suffered from flash burns. They say there have been no reports of serious life-threatening injuries.
    
The device burst into flames aboard a train at the Parsons Green station during the morning rush hour. London police are conducting a wide manhunt for the person or persons responsible.
    
___
    
6:05 p.m.
    
Britain's prime minister says U.S. President Donald Trump has called to offer his condolences over the subway attack.
    
Downing Street said in a statement that Trump telephoned Prime Minister Theresa May to discuss the "cowardly" rush-hour bombing attack Friday on a London subway train.
    
Officials say the two also talked about North Korea's latest missile test.
    
Earlier, May said speculation about the London subway bomber is unhelpful, after Trump suggested in a tweet that London police missed an opportunity to prevent it.