Zaydi Shiite rebels in north Yemen said they had taken control of a district, while a UN aid group canceled a cross-border humanitarian convoy. “Citizens took full control of government buildings” in the administrative district of Munabbih, a rebel statement late Wednesday said. It said local residents had turned against the authorities because of rights abuses. A government security source issued a statement saying the army had killed 62 rebels, referred to as Houthis after their leaders' clan, in mountainous Saada province where most of the Zaydi Shiites, a third of Yemen's 23 million population, live. The United States fear that fighting in the north of Yemen, and frequent street clashes with separatists in the south, could create instability that Al-Qaeda could exploit. It has already staged a comeback in Yemen in the past two years, with attacks on government and foreign targets. The United Nations High Commissioner for Refugees (UNHCR) delayed an aid convoy that was due to arrive this week. Around 150,000 civilians have been displaced since fighting first broke out in 2004, and international aid group Oxfam warned last month of an impending humanitarian crisis. Yemen has sought to drum up Arab support for the government. Arab League chief Amr Moussa said Tuesday Arab states supported the unity of Yemen. Egypt's President Hosni Mubarak and his intelligence chief Omar Suleiman met the Yemeni president in Sana'a a few days before.