“Oscar Fernandez-Taranco has arrived and will begin meeting Iraqi officials on Monday,” UNAMI spokesman Said Arikat said.

A UN official, speaking on condition of anonymity, said Fernandez-Taranco would meet cabinet ministers and foreign ministry officials.

His trip follows intense lobbying by Iraq for an independent probe into massive attacks in central Baghdad in August and this past Sunday.

On Wednesday, UN chief Ban Ki-moon told a news conference in New York that he would send Assistant Secretary General Fernandez-Taranco to Baghdad “in response to a request from the government of Iraq.”

“As elsewhere,” said Ban, “these acts of violence target the innocent and aim to disrupt the country’s fragile democracy.”

Twin suicide vehicle bombings targeting government offices in central Baghdad last Sunday (October 25) killed 153 people and wounded more than 500.

Al-Qaeda in Iraq claimed the attacks in an online statement.

Similar attacks on August 19, also against government buildings, killed around 100.

At the UN General Assembly last month, Iraq’s President Jalal Talabani called on the world body to create an independent international commission to investigate major attacks that have hit his country since last year.

Talabani said that by their nature and size, such attacks could have been carried out only with outside help.

Baghdad has accused neighbouring Syria of harbouring the masterminds behind attacks and Prime Minister Nuri al-Maliki alleges that 90 percent of foreign militants who infiltrate Iraq do so via Syria.