British Special Forces Advise Kenyan Counter terrorism Operation
British special forces have been deployed to the scene of an attack at a shopping center in Nairobi, Kenya.[1,2]
The British press reports that 'special forces', MI6 operatives and Metropolitan police are in Kenya to provide advice authorities carrying out the counter terrorism (CT) operation at the Westgate shopping complex, scene of a brutal terrorist attack and subsequent hostage crisis. There is no indication at this time that British involvement has gone beyond providing advice, although the Telegrpah claims the SAS 'were on standby to take part'.
It is perhaps not surprising that Kenyan authorities would seek help from British special forces. Aside from their reputation with such matters, a series of reports in recent years have told of British special forces activity in the region, including Kenya and neighboring Somalia.
In May of this year, it emerged that one of the suspects in the Woolwich street killing had been previously captured by an SAS team in Kenya. 
Earlier reports state that the SAS have been working with Kenyan forces in a covert campaign against Al Shabaab militants working out of Somalia, which shares a border with Kenya. Al Shabaab is an Al-Qaeda affiliate believed to be behind the attack at the Westgate shopping centre.
Another report, this time from late 2012, claimed that the SAS were hunting for Samantha Lewthwaite, aka 'the White Widow', a radicalized British woman and widow of one of the 7/7 bombers, who is thought to be behind several terror attacks in Kenya. Reports of a white female attacker spotted among the terrorists in the Westgate attack have led to speculation that Lewthwaite is involved in this latest atrocity.
more info / further reading:
- 1. SAS on hand as Kenyans launch final offensive in terror shopping centre
- 2. Kenya siege: UK officials investigate claims Britons were involved in attack
- 3. SAS Captured Woolwich Suspect 3 Years Ago
- 4. British Special Forces Operating In Somalia?
- 5. SAS Hunt White Widows