An explosion in the doorway of a pub is thought to have been caused by a device packed with nails, Scotland Yard said.
Staff say it was a miracle that no one was injured after the explosion tore through the Lady Margaret Pub, in Southall, west London, last night.
Police were today investigating whether the blast was connected to shots being fired near the pub about half an hour before the explosion.
A spokesman for Scotland Yard said: "Early assessment of the device indicates it probably contained a black powder which originated from fireworks and a substantial number of galvanised nails.
"The area will be cordoned off whilst a forensic search of the area is carried out."
Police confirmed that there had been a firearms incident near the pub but that there had been no reports of injuries.
There have been no arrests and police inquiries are continuing.
"It is not known at this stage if the two incidents are related," said thespokesman.
The force of the explosion at the entrance to the pub in Lady Margaret Road at around 10.50pm smashed windows and wrecked the door.
A couple of dozen regulars were still in the pub but no one was injured.
The pub was cordoned off as police bomb disposal experts spent several hours at the scene.
Pub assistant manager Sue Day said: "It was very frightening. We were getting ready for closing and suddenly there was this loud bang.
"The windows went in in the doorway and the pub filled with smoke.
"I have no idea why someone put the bomb there but it is a miracle no one was hurt."
Fire and ambulance crews were called to the scene but were not needed.
Customers were also allowed to leave shortly after the police arrived but part of the pub remained cordoned off.
The assistant manager added: "The door is very badly damaged and all the windows in the doorway shattered. It's a mess.
"It's just not something you expect to happen, especially when you are coming to the end of the night."
Deputy Assistant Commissioner Alan Fry, head of Scotland Yard's Anti–Terrorist Branch, said today: "This incident had the potential to cause injury and even death. It is made worse by the concerns that all people will have at this moment in regard to terrorist activity.
"Any use of explosives for whatever purpose in London will always be dealt with the utmost seriousness and it is essential those responsible be brought to justice."
Anyone with information should contact the Anti–Terrorist Branch on 0800 789 321.Reuse content