At least 16 civilians were wounded in shelling in the Yemeni besieged city of Taiz, the international aid agency Medecins Sans Frontieres (MSF) said on Twitter on Tuesday.

"As a result of yesterday's shelling of predominately civilian areas in Taiz city and its surrounding, MSF-supported Al Thawra Hospital has received 16 casualties so far, including women, elderly and children," said the aid agency.

It reiterated its call to all armed groups to abide by International Humanitarian Law and take all necessary precautions to avoid civilian causalities.

Meanwhile, residents in Taiz told Xinhua that a woman was also killed in the artillery shelling on Monday night.

Taiz city, in the southwest of the war-torn country, has been under tightening siege by the Houthi rebels since 2015.

Yemen has been mired in civil war since late 2014, when the Iran-backed Houthi group seized control of much of the country's north and forced the internationally-recognized government of President Abd-Rabbu Mansour Hadi out of the capital Sanaa.