Police and security services are reviewing the security in place around Parliament and other key London institutions after a soldier was shot dead in the Canadian capital Ottawa.
Prime Minister David Cameron has said that meetings were being held to make sure that security and intelligence services have "all the angles covered".
Speaking to the BBC's Asian Network, he said:
I was actually in a meeting with the Metropolitan Police Commissioner and the head of MI5 when the news about Ottawa broke.
They immediately reassured me that they had been looking at the security of institutions in central London but they would look again, obviously, to see if there is anything more that can be done and those meetings are taking place this morning.
Obviously what's happened in Canada is a very tragic event. Lives have been lost, including the life of a soldier, and it shows that we have to be permanently vigilant against this sort of terrorist threat.
Here in the UK we are very vigilant and, as I've said, meetings are taking place to make sure that we have all the angles covered.
British Airways has updated its guidance on broken or "uncharged" electronic devices, and now says customers can have them posted to an address of their choosing in order to fly.
Previously, BA had warned that customers found in possession of a device that would not turn on would be forced to miss their flight.
The airline now says that passengers can rebook if they wish to carry the device in their hand luggage, or have it either posted or ready to collect on their return.
Here are a few quick tips on how to save battery life of electronic devices and ensure trips abroad are not delayed.Read the full story ›
The Government is "constantly" reviewing new leads to potential security threats to the UK, the Transport Minister told Good Morning Britain.
Patrick McLoughlin tried to reassure the public the Government was doing everything it could to keep air passengers safe after it asked anyone flying to or from the UK to keep their mobile phones switched on through security checks.
However, the Conservative minister refused to say what the security threat was "we don't go into the exact details of the information we've received."
All air passengers flying into or out of UK airports have been advised to make sure electronic devices in their hand luggage are charged before they travel.
The updated guidance has been issued by the Department for Transport "in line with the US advice".
A DfT spokesman said, "Passengers flying into or out of the UK are therefore advised to make sure electronic devices being carried in their hand luggage are charged before they travel."
New rules on flights mean passengers could face having electronic devices taken from them if they do not switch on.Read the full story ›
British Airways passengers who attempt to board a plane to the United States with an uncharged electronic device will not be allowed to fly, the airline has announced.
The measure follows new rules enforced in the US which stated that mobile phones, laptops, tablets and other devices without power would not be allowed onto flights in hand luggage.
In response, new British government guidelines say devices that do not switch on would not be allowed on to aircraft bound for the States.
Meanwhile British Airways has taken the extra step of telling customers that customers who bring broken or uncharged devices will have to re-book.
Uncharged phones and laptops will be barred from planes going to the US under new security measures, the US Transportation Security Administration (TSA) said.
The new rules come amid growing concern about the increased capability of al-Qaeda affiliates in Yemen and Syria, and the threat the foreign fighters of Syria pose to the home countries.