A guard sits at the site of a Saudi-led air strike in Yemen's capital Sanaa, Feb 27, 2016. [Photo/Agencies]

UNITED NATIONS - UN Secretary-General Ban Ki-moon on Sunday called for "a prompt and impartial investigation" into the Saturday airstrike on a market in Yemen that killed at least 32 civilians.

In a statement issued here by his spokesman, Ban "strongly condemns the apparent airstrike" on Khaleq market in Nehm district in northeastern Sanaa, whose death toll was among the highest from a single bombing since September 2015.

The bombardment, reportedly carried out by the Saudi-led Arab coalition, also left at least 41 others injured. Other reports put the death toll around 45.

"The secretary-general is concerned about the continuing intense airstrikes and ground fighting in Yemen despite his repeated calls for a cessation of hostilities," the statement said.

The secretary-general expressed his sincere condolences and sympathies to the families of the victims, said the statement.

"The secretary-general reminds all parties to the conflict of the utmost necessity to fully respect their obligations under international human rights law and international humanitarian law, which prohibits attacks directed against civilians and civilian objects, including populated markets," the statement said.

"The secretary-general stresses that such attacks are considered serious violations of international humanitarian law," it added.

Meanwhile, the statement said that "the secretary-general reiterates his call on all parties to the conflict in Yemen to engage in good faith with his special envoy for Yemen in order to agree on a cessation of hostilities as soon as possible and to convene a new round of peace talks," it added, referring to Ismail Ould Cheikh Ahmed, who has been engaged in painstaking efforts to mediate a political solution to the current Yemeni conflict.

Yemen has been mired in an all-out civil war since September 2014, when the Shiite Houthi group, backed by forces loyal to the former president, invaded Sanaa and drove President Abd Rabbu Mansour Hadi into exile.

The Saudi-backed Yemeni government forces have advanced to within 50 km from Sanaa earlier this month, after recapturing military posts in Nehm district and its mountains overlooking the rebel-held capital from the northeast.

The advance, backed by Saudi-led warplanes, came very slowly because of the rebel-planted minefields in the roads ahead toward Sanaa.

The Saudi-led coalition started daily air bombings on the Shiite Houthi rebels and their allied forces since March 2015, vowing to drive out the rebels and retrieve the capital.

More than 6,000 people have been killed in ground battles and airstrikes, half of them civilians.