(CNN) -- A member of Yemen's parliament was shot dead by armed gunmen in Sanaa Friday, three senior Interior Ministry officials told CNN.
"Abdul Karim Jedban was on his way home when he was shot by gunmen on a motorcycle," a senior official said on condition of anonymity because of the sensitivity of the issue.
The officials said in a separate incident but in the same area of Sanaa, a United Nations convoy was shot at, although the U.N. envoy who was traveling to his hotel was not injured.
But according to state news agency SABA, an official source at the office of U.N. envoy Jamal Benomar denied that the convoy came under fire, saying reports of such an incident were unfounded.
The killing of Jedban, who represents the pro-Shiite Houthis in the National Dialogue Conference (NDC), is a major blow to the country's transitional period and international efforts seeking political progress in Yemen. The U.N.-backed NDC reconciliation talks are aimed at drafting a new constitution and laying the groundwork for elections to be held next year.
Houthi spokesperson Hasan al-Hamran condemned the killing of Jedban and demanded immediate answers from the government. He said that the latest killing raises serious worries. "The killing of Jedban hurts the political progress," said al-Hamran.
SABA reported that Yemen's President, Abdu Rabu Mansour Hadi, has ordered an investigative committee headed by several prominent officials to investigate the incident as soon as possible,
Friday's violence comes two days after a third ceasefire went into effect and hundreds of peacekeeping forces were deployed to the northern province of Sa'ada, where more than 150 people have been killed over the last month in clashes between the Shiite Houthis and hardline Sunni fighters.
Hours after the ceasefire, two peacekeeping soldiers were killed on duty when a mine exploded as a military vehicle passed by.
Following several failed attempts at a truce in the north, Yemeni officials and the international community worry tensions in Sa'ada will mar the NDC and prevent representatives from securing an end resolution to Yemen's lengthy transition of power.
Al-Hamran told CNN that certain factions are choosing to support sectarian violence under the aim of halting any success within the national dialogue. The Houthis have accepted the ceasefire but certain factions benefit and do not want to see stability, said al-Hamran.
Experts say that Yemen as a country stands to lose should sectarian strife emerge and add to the impoverished nation's long list of afflictions.
"Yemen had enough to worry about even before the sectarian violence," said AbdulSalam Mohammed, president of the Abaad Research Center. "Arms are everywhere and the national dialogue cannot succeed without a strong central government and control over all areas of the country."
CNN's Hamdi Alkhshali contributed to this report.