American and Iraqi efforts to improve security in Baghdad have failed to reduce bloodshed in the increasingly violent Iraqi capital, the senior US military spokesman in Iraq acknowledged on Thursday.

In an uncharacteristically gloomy admission, Major General William Caldwell said the recent surge in violence was “disheartening”. He said US and Iraqi forces would have to “refocus” security measures. The review was demanded by General George Casey, who commands the 140,000 US troops in Iraq.