No one immediately claimed responsibility for the attack, but the Islamic State of Iraq and the Levant (ISIL) group has carried out similar attacks as previously.
The UN said earlier this month that some 600,000 civilians were still in west Mosul, 400,000 of them trapped in siege-like conditions in the Old City.
In a Thursday statement, the United Nations Assistance Mission for Iraq (UNAMI) said Guterres' visit would focus mainly on the deteriorating humanitarian situation in and around Mosul. Of those an estimated 76,000 people have returned to their areas, but suffering lack of services.
Iraqi forces are fighting Daesh in Iraqi city of Mosul, where some 2,000 fighters are launching fierce counterattacks.
The visit comes several days after a reported US-led airstrike left over 230 civilians dead in western Mosul. After the beginning of the operation to retake Mosul in October, Iraqi authorities in January declared they liberated eastern Mosul, which is separated from the city's western neighbourhoods by the Tigris River.
OPEC compliance with oil curbs rises in March as UAE joins cut
ET release, USA benchmark West Texas Intermediate oil contracts for May delivery were trading up 1.4% to above $49 a barrel. USA crude exports almost doubled last week to climb over 1 million bpd, EIA data showed.
Guterres is scheduled to meet top Iraqi officials, including Prime Minister Haider al-Abadi before heading to Arbil, the capital of the country's semi-autonomous Kurdistan region.
A suicide truck bomb blew up at a checkpoint in the south of the Iraqi capital Baghdad on Wednesday night, killing at least 17 people and wounding more than 60, Iraqi officials said.
First Lt. Walid Khalid of the 3rd brigade Federal Police said his troops advanced about 100 metres (yards) in the last two days.
"The distance between IS and us is 50 meters, yesterday, we killed four IS fighters and right now their bodies are in the street". "The situation is very good and the Iraqi air force is doing well".