A combination of video grabs (L-R, top to bottom) shows U.N. Secretary-General Ban Ki-moon (R) and Iraq's Prime Minister Nuri al-Maliki reacting to an explosion during a news conference in Baghdad March 22, 2007. Ban was left shaken but unhurt on Thursday on his first visit to Baghdad after a Katyusha rocket landed just metres from a building where he was giving a news conference.(Xinhua Photo)

An explosion rocked the heavily fortified Green Zone in Baghdad on Thursday while Iraqi Prime Minister Nuri al-Maliki and visiting UN Secretary General Ban Ki-moon were holding a joint news conference.

The explosion was heard clearly at the news conference held following the talks between Ban Ki-moon and al-Maliki. According to some reporters who ran out of the room to see what happened, the blast left a big crater only some 50 meters away from the conference building.

The explosion caused an obvious shock on the footage of a live broadcast of the news conference aired by the pan-Arab satellite al-Jazeera TV, from which Ban was seen taken aback and apparently shocked by the blast while small chips of debris floating down from the ceiling.

An Interior Ministry source said the blast was caused by a mortar round landed near the conference building, and the casualties caused by the blast are yet to be determined.

Prior to the explosion, al-Maliki said in his speech that Ban's visit to Baghdad is a sign that Iraq is on the right way to stability.

"We consider the visit a positive message to the world that Baghdad has returned to receive important figures because of the success in the political process and stability," al-Maliki said.

For his part Ban asserted his organization's stance in supporting the Iraqi people and its government.

"I am here to reaffirm strong commitment of the UN and international community to the Iraqi people and its government," Ban said.

In the wake of the explosion, the news conference was hastily ended after about only two questions.

Ban arrived Baghdad on Thursday morning for his first visit to Iraq after he took over from Kofi Annan as UN chief. He was expected to spend only one day here to have talks with al-Maliki.

Editor: Yan