Iraqi Prime Minister Nouri al-Maliki, right, shakes hands with UN Secretary General Ban Ki-moon ahead of their meeting in Baghdad, 22 Mar 2007

U.N. Secretary-General Ban Ki-moon has paid a surprise visit to Baghdad. VOA's Margaret Besheer reports from northern Iraq, that Mr. Ban got an unpleasant taste of what life is like for ordinary Iraqis, when a mortar landed directly outside the building where he and Iraq's prime minister were holding a news conference.

The Secretary-General was visibly shaken, briefly ducked for cover, but was unhurt after the blast that appeared to be from a mortar.

It fell directly outside the building where the press conference was being held in the heavily-protected Green Zone.

As security guards tried to usher Iraqi Prime Minister Nouri al-Maliki out of the room, he calmly told them nothing was wrong and the press conference continued for a few more moments until officials abruptly ended it.

Moments before the blast, Mr. Ban said he would reconsider expanding the U.N. presence in Iraq once the security situation has visibly improved.

"This is one of the subjects which I have discussed and I will consider on the basis of my assessment of this visit," he said.

The United Nations scaled back its presence in Iraq after the August 2003 bombing of its Baghdad headquarters killed 22 staffers, including top envoy Sergio Vieira de Mello.

In a separate development, the U.S. military announced it has released into Prime Minister Maliki's custody an aide to radical Shi'ite cleric Moqtada al-Sadr.

Sheikh Ahmed Shibani was detained two-and-one-half years ago in the southern city of Najaf.

In a televised meeting with Mr. Maliki, the cleric pledged his help in making the government's attempts at peace and reconciliation a success.

The warm reception for the cleric underlines the close ties Mr. Maliki has to Moqtada al-Sadr, whose support won Mr. Maliki his job last year. Iraqi officials say they have been holding talks with various insurgent groups in an effort to stabilize the security situation.