July, against all parts of royalist Yemen. Casualty estimates vary, and an assumption, considered conservative, is that the mustard and phosgene-filled aerial bombs caused approximately 1,500 fatalities and 1,500 injuries. 1994 Civil War During the 1994 Yemeni Civil War almost all of the actual fighting in the 1994 civil war occurred in the southern part of the country despite air and missile attacks against cities and major installations in the north. Southerners sought support from neighboring states and received billions of dollars of equipment and financial assistance, mostly from Saudi Arabia, which felt threatened during Gulf War in 1991 when Yemen supported Saddam Hussien. The United States repeatedly called for a cease-fire and a return to the negotiating table. Various attempts, including by a UN special envoy, were unsuccessful to effect a cease-fire. Southern leaders declared secession and the establishment of the Democratic Republic of Yemen (DRY) on 21 May 1994, but the DRY was not recognized by the international community. Ali Nasir Muhammad supporters greatly assisted military operations against the secessionists and Aden was captured on 7 July 1994. Other resistance quickly collapsed and thousands of southern leaders and military personnel went into exile. 2011 Yemeni Revolution In March 2011, a month after the beginning of an uprising against President Saleh's rule, Maj. Gen. Ali Mohsen al-Ahmar, the commander of the 1st Armoured Division, defected to the side of the protesters taking hundreds of troops and several tanks to protect protesting citizens. Rival tanks of the 1st Armoured Division and the Republican Guard faced off against each other in Sann'a. The Yemeni Army's 119th Brigade, which had defected to the opposition, launched a joint operation with 31st and 201st Brigades which were still loyal to Saleh and retook the city of Zinjibar on 10 September from Islamist militants who were exploiting the chaos in the country to expand their influence. The offensive relieved besieged army units in the process. On 17 September, at least one rebel soldier was killed in clashes with loyalists in Sanaʽa near the city's central square, trying to protect the protest camp there from security forces. After anti-government tribesmen overran a loyalist army base north of Sanaʽa on 20 September, capturing 30 soldiers, the government responded with airstrikes killing up to 80 civilians. Houthi takeover in Yemen During the revolution of 2011, large crowds of Houthis participated in the protests. When the armed uprising started,