The U.N. envoy to Yemen said militants linked to al-Qaida are working to undermine political development in the country. Ali Abdullah Saleh resigned as president of Yemen in February after enduring a year of demonstrations staged in opposition to his government. Violence attributed to al-Qaida in the Arabian Peninsula increased since Abdu Rabo Mansour Hadi took over the presidency. A day after a suicide bomber in the Yemeni capital Sanaa targeted police cadets, U.N. envoy Jemal Benomar said insurgents in the country were hampering political development, the BBC reports. Al-Qaida affiliate Ansar al-Sharia is believed to be responsible for the attack in Sanaa, though no group has come forward to take credit for the bombing. Ansar al-Sharia was tied to a May bombing in Sanaa that killed 90 soldiers, the deadliest attack since Hadi came to power. The security situation in Yemen has deteriorated in large part due to fighting between pro-government forces, supported by the United States, and al-Qaida in the Arabian Peninsula, the Yemeni branch of al-Qaida. A Security Council resolution passed in June calls on Yemen to convene a national dialogue, restructure the military under a unified command and implement political reform with the aim of general elections in 2014.