NAIROBI MALL ATTACK: 3 British Nationals among the 59 killed at Westgate shopping centre.

A rescue worker helps a child outside the Westgate Mall in Nairobi, Kenya on Saturday, September 21, 2013, after al-Shabab gunmen opened fire and reportedly threw grenades during an attack that left dozens dead and wounded. 

Kenyan minister says death toll is now up to 59, as shots are fired on troops preparing hostage rescue operation.

Three British nationals have been killed in the Westgate shopping centre Nairobi terrorist attack, and that number is set to rise, the Foreign Office has said.

Kenyan security forces are locked in a standoff with an estimated 10 to 15 heavily armed gunmen believed to be linked to the Islamist Somali al-Shabaab group, with the tense security operation marked by occasional bouts of gunfire.

Soldiers carried children and led other victims to safety as armed police combed the shopping centre 

Earlier the country’s Interior Ministry said the death toll currently stands at 59, with a further 175 injured, and despite having “complete control” of the situation and access to the shopping centre’s CCTV systems, there is still no definitive count on the number of hostages held inside.

The British Foreign Office issued a statement which said UK staff had been sent to Nairobi to provide consular support, and the Government’s crisis committee – chaired by Foreign Secretary William Hague – met to discuss the situation.

Prime Minister David Cameron said: “It is an absolutely sickening and despicable attack of appalling brutality. Because the situation is ongoing, we should prepare ourselves for further bad news.”

In an address to the nation this afternoon, Kenyan President Uhuru Kenyatta said that his nephew and fiancée were among those who died in the attack.

A wounded woman outside the shopping centre in Nairobi. 

He said that while investigations were ongoing to confirm al-Shabaab's involvement, the terrorists “would not get away with their despicable and beastly acts”.

“We will punish the masterminds swiftly and indeed very painfully,” Mr Kenyatta said, adding that “the cowardly perpetrators are now cornered in the building”.

Deputy President William Ruto has asked judges at the International Criminal Court to adjourn his case so that he can return home to provide assistance. He stands trial for alleged involvement in violence after the 2007 Kenyan elections.

Meanwhile, Israel has confirmed that its security officers have joined the effort to resolve the hostage situation. Members of its military will provide negotiation and strategic assistance, but will not be involved directly if an armed offensive is required.

Yesterday gunmen armed with grenades, AK-47s and ammunition belts opened fire inside the affluent mall during a children’s cooking competition, leaving shoppers – many of whom were ex-pats and tourists – fleeing for their lives.

The security effort has been ongoing since then, with a reported 1,000 people rescued from the situation so far.

Military reinforcements arrived this morning, according to the Interior Ministry, with armoured vehicles bringing more soldiers to join in the rescue operation. At approximately 11am (9am BST), fresh barrages of gunfire were heard from within the shopping centre as security forces ran in a line and crouched along the front of the building.

Speaking to reporters today, Interior Minister Joseph Ole Lenku insisted the police and army were in complete control of the situation, but a message from the Twitter profile for his office asked that media organisations stop broadcasting the specific movements of troops outside – reportedly assisting the terrorists in doing so.

Today’s movements at the scene come as security forces try to establish the number of hostages within the building – thought to be around 30 – with several of those trapped in the building overnight having been able to escape on their own.

Injured customers escape gunmen

Nairobi's Police Chief, Benson Kibue, yesterday described the assault as a terrorist attack, and last night the Somalia-based group al-Shabaab was reported to have claimed responsibility.

A rescuer carries a child to safety at the Westgate mall in Nairobi, Kenya, after an attack claimed by al-Shabaab militants

According to eye-witnesses, the gunmen told Muslims to leave the centre shortly before midday and said that non-Muslims would be targeted.

Some claimed the attackers had asked, “who is Prophet's mother?” in an attempt to discover non-Muslims. One man escaped by showing the attackers his ID with his name, Hakim, on it. Another reportedly failed to name the Prophet's mother and was killed.

Civilians who had been hiding walk to safety with their hands up

Who Are al-Shabaab?

Islamist extremism has been on the rise in East Africa for the past decade, with al-Qa'ida-linked groups such as al-Shabaab behind a growing number of terror attacks.

Since the Kenyan army began helping Somali forces tackle al-Shabaab insurgents in southern Somalia in October 2011, Kenya has fallen victim to a string of retaliatory gun and grenade attacks.

Last month, four Kenyan police officers were shot dead in Garissa, near the Somali border, when 40 armed men suspected of belonging to al-Shabaab attacked a police post. In July, the group released two Kenyan government officials it had seized in a 2012 cross-border attack, after holding them hostage in Somalia for more than a year.

Between July 2011 and July 2012 there were at least 17 attacks involving grenades or explosive devices in Kenya, killing at least 48 people and injuring around 200. Four of these attacks occurred in Nairobi, and four in Mombasa. Targeted locations have included police stations and police vehicles, nightclubs and bars, churches, a religious gathering, shops and a bus station.

Al-Shabaab was also behind the twin bomb attacks in Kampala, Uganda, that killed at least 74 people in 2010. These were again connected to military actions against them in Somalia. Sheik Ali Mohamud Rage, the group's spokesperson, said soon after the bombings: “We are sending a message to Uganda and Burundi, if they do not take out their Amisom [African Union Mission in Somalia] troops from Somalia, blasts will continue and it will happen.”

Today, the group added: “The Kenyan government turned a deaf ear to our repeated warnings.”