Britain's foreign secretary held talks Thursday with Prime Minister Nouri al-Maliki as at least 13 people were reported killed in the ongoing fighting between Shiite militiamen and Iraqi and U.S.-led forces, according to AP. The British Embassy confirmed that Foreign Secretary David Miliband had arrived on a previously unannounced visit but refused to release any other information due to security concerns. Britain has around 4,500 troops in Iraq, most of them based at an airport camp near the southern city of Basra. Britain suspended plans to withdraw about 1,500 troops this spring after fighting broke out last month between Iraqi forces and Shiite militiamen. In the latest clashes, five people died and 28 were wounded early Thursday in Baghdad's embattled Sadr City district, a stronghold of the Mahdi Army militia of anti-American cleric Muqtada al-Sadr. Another eight people were killed and two wounded during fighting in the capital's Husseiniyah area, another base of Shiite militants. The fighting broke out after Iraqi troops moved last month to regain control of Basra, capital of the country's vast oil industry from militias. U.S. and British troops have helped the Iraqis gain control of the city, although scattered attacks still occur.