An al-Shabaab propaganda video aimed at potential recruits in Britain is compelling evidence of a UK link to this growing militant group.
An Al-Shabaab recruitment video makes reference to 10 British militants, raising the possibility of links to the attack on a mall in Kenya.
British investigators are struggling to pierce the secrecy surrounding Kenya's Westgate mall attack.
Two terrorist attacks on the Kenyan coast was not orchestrated by the al Shabaab terrorist network, according to the country's president Uhuru Kenyatta.
Mr Kenyatta said the 65 people were killed by "local political networks", dismissing claims by Somalia's al Shabaab Islamist group that it was behind the assaults.
Speaking to the nation, he said:
"This was not an al Shabaab terrorist attack. Evidence indicates local political networks were involved in the planning and execution of the heinous crime.
"This also played into the opportunist network of other criminal gangs," he said.
Somali-linked Islamist militants, who claimed responsibility for two nights of attacks on Kenyan coastal towns, have said they will "continue" operations in the country.
"We raided villages around Mpeketoni again last night," Sheikh Abdiasis Abu Musab, the spokesman for al Shabaab's military operations told Reuters.
The group also said it had killed as many as 20 people, mostly police, stating: "Our operations in Kenya will continue."
Mbeketoni eywitnesses say Al-Shabaab gunmen executed men in front of their families and killed others who had gathered to watch World Cup football on television.
"The attackers were so many and were all armed with guns. They entered the video hall where we were watching a World Cup match and shot indiscriminately at us," Meshack Kimani said, adding about 10 people were killed there.
"They targeted only men but I was lucky. I escaped by hiding behind the door," he said.
Al-Shabaab, the Islamist terror group claiming responsibility for yesterday's killings, has issued a warning to tourists.
In a statement, the group said, "Kenya is now officially a war zone and as such any tourists visiting the country do so at their own peril."
Al-Shabaab has claimed responsibility for the deadly attacks in Kenya yesterday.
In a statement, the Somali Islamist group said, "Commandos last night carried out a successful raid on the town of Mpeketoni."
As reasons, it cited the deployment of Kenyan troops to Somalia, and what it called Kenya's extra-judicial killings of Muslim scholars - a charge Nairobi has denied.
The UK Government says travelers should not go within 60km of the Kenyan border with Somalia unless absolutely necessary, because of the threat from terrorist group Al-Shabaab.
Yesterday's attack happened in Mpeketoni, just south of the popular resort of Lamu. This is not within the orange danger zone, though the Foreign Office has today updated its website to make travelers aware of the killings.
A spokeswoman at the Foreign & Commonwealth Office said the travel advice is kept under constant review.
Al-Shabaab, the Somali Islamist group with links to Al-Qaeda, has claimed responsibility for yesterday's attacks, according to the pro-Shabaab website Somalimemo.
It goes on to claim that the attacks were revenge for the killing of Muslim clerics.
Kenya sent troops to Somalia in 2011 to help the UN-backed government defeat Al-Shabaab.
Kenyan police say Somalia's Al-Shabaab Islamist group is most likely to blame for Sunday night's assault on the town of Mpeketoni.
There has been no immediate claim of responsibility for the attacks, in which at least 48 men were killed.
Radical Islamist Anjem Choudary is reported to have featured in a video that threatened UK Muslims, according to the Daily Telegraph.
Mr Choudary allegedly called David Cameron and Home Secretary Theresa May "pathetic foolish leaders".
The preacher told the newspaper: “I am happy for what I say anywhere in the world in any clip because at the end of the day I believe that I speak what is right according the divine texts.
“If they want to use that clip I don’t have any problem with that at all.”
UK-based imam and broadcaster Ajmal Masroor has written on his Facebook page that two Metropolitan police detectives arrived at his home on Wednesday night to warn he was "in imminent danger from the terrorists."
The police officers were visiting me to give me a warning and asking me to be more vigilant.
As soon as they left my house I started digging further and found an al-Shabab video has been uploaded on the internet and in it they name me as a Muslim who is an enemy of Islam and should be eliminated.
They name a few others in their video message and encourage people to resort to using knives to behead people like me.