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.
The ‘White Widow’, Samantha Lewthwaite, may be the most notorious, but 50-100 young British Muslims have joined al Shabaab as 'jihadists'.
African countries could set up a special fund to combat Islamist militant groups, the continent leaders proposed on African Union Peace and Security summit in Nairobi.
Kenya's President Uhuru Kenyatta said African countries should stand together against the threat of Boko Haram and Al-Shabaab.
Al-Shabaab militants killed 67 people in a raid on a shopping mall in Kenya last September.
"No single state can tackle this threat alone," Mr Kenyatta said. "It is particularly worrying in Africa today that terrorist organizations have grown both in terms of number and capability."
We emphasised the need to address all the conditions conducive to the spread of terrorism and violent extremism http://t.co/BN1B1AWkrF
The idea of a common African fund to combat terrorism was mooted by Mr Kenyatta and would be discussed at the next African Union summit.
A leader of Somalia's al Qaeda-linked militants Ahmed Abdi Godane was the target of an US air strike in Somalia, an US official said.
It is not clear whether the Al-Shabaab leader was hit in the strike, the official added.
Six militants were killed in the attack on two vehicles that were heading toward the coastal town of Barawe, Al-Shabab's main base.
Since taking charge in 2008, Godane has restyled the group as a global al Qaeda player - a transformation that was highlighted when it killed at least 67 people in an attack on a Kenyan shopping mall last September.
An US airstrike hit an area where leaders of Somalia's al Qaeda-linked militants were meeting, intelligence sources told Reuters.
The strike prompted rumours among Somali government officials that it had targeted al-Shabaab leader Ahmed Abdi Godane and other leaders who were suspected to have been at the location, but there was no confirmation they were hit.
Since taking charge in 2008, Godane has restyled the group as a global al Qaeda player - a transformation that was highlighted when it killed at least 67 people in an attack on a Kenyan shopping mall in September.
The US Department of Defence said that its forces had carried out the operation against al-Shabaab and would provide more information "when appropriate".
Five suspected Islamist militants have been killed in an attack on the Somali presidential compound, the east African country's interior minister has said.
Al-Shabaab had earlier claimed to have had control of some areas of the compound, but the Somali authorities say the security forces are now in control of the area.
Somali security forces have now re-taken control of the presidential palace after a raid by Al-Shabaab militants, the country's interior minister is reported as saying.
The minister added that president, Hassan Sheikh Mohamoud, was not harmed in the raid as he was elsewhere at the time.
The Somali presidential palace is under attack by Al-Shabaab militants, a spokesman for the terror group said.
"The militants have partly entered the presidential palace compound. There is periodic gunfire now," an official in the presidential palace who asked not to be named told Reuters. "I understand most attackers have been killed. No further details."
Al Shabaab confirmed they were involved. In a statement they said: "We have entered the so-called presidential palace. We have now captured some parts of the palace and fighting is still going on."
Two soldiers are now confirmed to have died and a further four wounded after a car bomb exploded near a Somali parliament building hundreds of metres from the presidential compound, according to a government official.
Police said soldiers guarding the building prevented the bomb from reaching its target.
"The suicide car bomb was targeting the parliament entrance but it was fired on from all sides as it approached the main gate," said Nur Ahmed, a colonel in the police service.
At least one person was killed when a car bomb exploded near the Somali parliament building, Reuters reports.
Dahir Amin Jesow, a legislator in the house, told the news agency: "A car bomb occurred near the parliament house but we are all safe.
"I could see a dead soldier and three other injured soldiers outside parliament's compound which is safe."
The parliament building is a few hundred metres from the presidential compound.
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.
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.