Foreign Secretary William Hague has condemned the bomb attack on a UN building in Nigeria and pledged that Britain stands ready to provide assistance.
Mr Hague said he was "shocked" to hear of the blast in Abuja which is reported to have killed at least 16 people.
He said: "This brutal act has killed and injured many innocent people and I utterly condemn those who have carried it out. My thoughts are with the families, friends and colleagues of those affected."
He added: "Around the world the UN works for peace, security and international cooperation and an attack on the UN is an attack on these principles.
"We will be passing on condolences to the UN secretary general and President Jonathan. The UK stands ready to provide any assistance we can to the UN and Nigerian authorities to bring those responsible to justice."
Hospital workers said around 40 bomb blast casualties had been admitted for treatment so far.
Witnesses reported seeing a car smash through two sets of security gates at the UN offices, where around 400 employees are based.
The suicide bomber drove up to the main reception before detonating the explosives, causing widespread devastation.
Three large cranes were used to remove debris during the search for survivors.
No organisation has claimed responsibility for the attack but Nigeria has endured a campaign of attacks and assassinations in recent months, including by extremist Muslim faction Boko Haram which wants a hardline version of Sharia law to prevail in the mixed Christian-Muslim nation.