North Yemen received its first 64 M60A1s in 1980 as part of a $400 million arms transfer from the United States requested by Saudi Arabia to counter border disputes with the communist People's Democratic Republic of Yemen government of South Yemen. During the 1980s Saudi Arabia provided more M60s to North Yemen reaching a height of approximately 250 by 1990. With the collapse of communism, South Yemen was unified with the Yemen Arab Republic (commonly known as "North Yemen") on 22 May 1990, to form the present-day Yemen. After four years, however, South Yemen declared its secession from the north, which resulted in the north occupying south Yemen and the 1994 civil war. On 27 April, a fierce battle took place between Yemeni forces in the wadis east of Zingibar involving M60A1 tanks and infantry from Yemen's Amaliqa brigade. Opposing them were the 119th Brigade, which had defected to the opposition. Hundreds of Somali refugees were killed when their camp on the southern coast of Yemen was caught in crossfire between the two sides. The defeat of the DRY forces opened the way for the advance to Aden which fell on 7 July. Other resistance quickly collapsed and thousands of southern leaders and military went into exile. As of 2015, there are an estimated 50 M60A1s in service with the Yemeni Army. In February 2018, the Yemeni National Army launched Operation Restore Legitimacy, employing its armor units and artillery to defeat Houthi rebels in several areas east of the city of Hodeidah.