United Nations Secretary General Ban Ki-moon has called for stepped-up measures to protect UN personnel working for Afghanistan's second round of election on November 7. At an emergency meeting of the world body on Thursday night, it was decided to convene all heads of UN agencies and departments to discuss new security measures to protect staff, after a Taliban-led attack killed six UN staffers at a UN guest house in the Afghan capital of Kabul . Mr. Ban told reporters after a closed-door session that the UN has increasingly become targets because it supports the Afghan elections. The UN chief spoke by telephone with Afghan President Hamid Karzai, who promised to tighten security at UN mission compounds in Kabul. Mr. Ban Ki-moon called for support of member states to ensure security and warned that their staff was vulnerable to more attacks in the week leading up to the Afghan elections.<br/> Meanwhile, non-essential staff of some UN agencies based in Afghanistan and not involved in elections has been ordered to proceed on leave in run up to the elections. Most of UN staff remained under closed doors on Thursday and the security around their offices and residences were tightened in wake of Wednesday’s attacks.<br/>