An anti-Communist force made up of 1,500 FNLA fighters, 100 Portuguese mercenaries, and two battalions of the Zairian army passed near the city of Quifangondo, only 30 km north of Luanda, at dawn on 10 November. The force, supported by South African aircraft and three 140 mm artillery pieces, marched in a single line along the Bengo River to face an 800-strong Cuban force across the river. Cuban and MPLA troops bombarded the FNLA with mortar and 122 mm rockets, destroying most of the FNLA's armored cars and 6 Jeeps carrying antitank rockets in the first hour of fighting. The Cuban-led force shot 2,000 rockets at the FNLA. Cubans then drove forward, launching RPG-7 rocket grenades, shooting with anti-aircraft guns, killing hundreds. The South Africans, with their aged World War II-era guns were powerless to intervene, and subsequently retreated via Ambrizete to SAS "President Steyn", a South African navy frigate. The Cuba-MPLA victory at the Battle of Quifangondo largely ended the FNLA's importance in the conflict. On 25 November, as SADF armored cars and UNITA infantry tried to cross a bridge, Cubans hidden along the banks of the river attacked; as many as 90 South African and UNITA troops were killed or wounded, and 7 or 8 SADF armored cars were destroyed. The Cubans suffered no casualties. Between 9 and 12 December, Cuban and South African troops fought between Santa Comba and Quibala, in what became known as the "Battle of Bridge 14". The Cubans were severely defeated, losing 200 killed. The SADF suffered only 4 casualties. At the same time, UNITA troops and another South African mechanized unit captured Luso. Following these defeats, the number of Cuban troops airlifted to Angola more than doubled, from about 400 per week to perhaps 1,000. The Cuban forces mounted a counter-offensive beginning in January 1976 that impelled South African withdrawal by the end of March. South Africa spent the following decade launching bombing and strafing raids from its bases in South West Africa into southern Angola.