New York, June 1 (RHC)-- Human Rights Watch (HRW) says evidence shows Saudi Arabia has been pounding neighboring Yemen with internationally banned cluster bombs, warning that such attacks are "harming civilians."

In a report released on Sunday after a visit by HRW officials to Yemen's northern province of Sa'ada, the New York-based rights organization said the cluster bombs have targeted civilians and residential areas. The report said three types of cluster bombs have been used in the attacks.

The rights body also posted photos showing remnants of cluster munitions and unexploded submunitions found in several areas, including al-Nushoor and al-Maqash in Sa'ada.

"These weapons can't distinguish military targets from civilians, and their unexploded submunitions threaten civilians, especially children, even long after the fighting," said Ole Solvang, a senior researcher at the emergency division of the HRW.

Solvang further said all sides "need to recognize that using banned cluster munitions is harming civilians." He said: "Increasing evidence of cluster munition use raises concerns not just for civilians now, but for when the fighting is over."

The report also urged the supporters of the Saudi aggression against Yemen, particularly the United States, to condemn the use of the banned weapons by Riyadh. On May 3, the rights organization said photographs, video footage, and other evidence have surfaced since mid-April 2015, indicating that cluster munitions have been used in attacks on Sa'ada.

In August 2013, the U.S. Department of Defense agreed to provide Riyadh with 1,300 CBU-105 Sensor Fuzed Weapons manufactured by Textron. Yemen has been the target of incessant Saudi airstrikes since March 26th.