The foreign secretary Margaret Beckett has condemned the bomb blasts at the Iraqi parliament in Baghdad.
At least two MPs have died and witnesses report "many casualties" following an explosion in the Iraqi parliament in the city's heavily fortified 'green zone'.
The exact cause of the explosion is unclear but police suspect a suicide bomber may have detonated a device in the parliament cafe, where many MPs and guests were having lunch.
Ms Beckett expressed her condolences to the friends and families of those killed and injured in the "terrible act".
"I was deeply shocked and saddened to hear of this appalling attack on the democratically elected members of the Iraqi parliament going about their day to day business," she said.
Ms Beckett continued: "Nothing could highlight more the twisted minds of those who are seeking to disrupt the democratic process in Iraq. Those who carry out these outrageous attacks offer nothing to the Iraqi people except more murder and destruction.
"The Iraqi people have shown great fortitude and courage - they deserve our full and continued support."
Joining the condemnation of the attack, shadow foreign secretary William Hague said it demonstrated the challenges faced by a democratic Iraq.
"The fact that the latest attack has taken place within the green zone itself and that it targeted the Iraqi parliament, proves the enormity of the challenge for the emerging Iraqi democracy," he said.
Security forces have questioned how it was possible to smuggle a bomb into the heavily fortified parliament building. It is the first bomb blast inside the building, although the parliament has previously been hit by mortar attacks.
US and Iraqi forces had launched a security crackdown in a bid to combat the continued insurgency in Baghdad. But despite a reduction in the number of death-squad killings, suicide attacks and roadside bombings have continued.