DEN -- Northern Yemeni forces captured outlying districts of Aden on Wednesday, moving closer to its center on a rocky peninsula in what appeared to be a final push to overthrow the breakaway southern Yemen state. Egypt, Syria and five Gulf Arab states said they would take unspecified steps if the north pressed its attack on Aden, and Kuwait said this might mean recognizing the south. The north and the south are negotiating the surrender of those parts of Aden still in southern hands, according to southern political sources. The negotiations are said to be "under American sponsorship, to avoid further bloodshed in Aden."Describing the advance, one Aden resident said, "The northerners took Sheikh Othman and Mansoura and they are in some parts of Khormaksar. The city is almost split now. We're going to have a nervous time." Residents said troops loyal to northern President Ali Abdullah Saleh captured Sheikh Othman by midday Wednesday and then took the nearby Mansoura district, both north of the peninsula where central Aden lies. The Khormaksar site of Aden's airport, which has been a vital base for southern warplanes, was not operational Wednesday afternoon, according to residents. Large numbers of southern soldiers had deployed around Khormaksar and the crowded peninsula area of Crater, setting up Russian-made 12.7 mm heavy machine guns, residents said. But the only sounds of fighting late Wednesday afternoon were sporadic bursts of gunfire and occasional artillery fire to the north of Crater. "If there is fighting, the civilian casualties are going to be very, very high," one resident said. "Some people are suggesting going out and talking to the northerners." Egypt, Syria and five Gulf Arab states, meeting in Kuwait, said they would take whatever steps they found suitable to bring peace if Yemen's two-month long war continued. Their statement did not specify what this might involve, though it said the states would send aid to Aden. Kuwaiti Foreign Minister Sheikh Sabah al-Ahmad al-Sabah told reporters one possible step was recognition of the south, losing its war to break free from a four-year union with the more populous, conservative north. The small Gulf state of Qatar, which has shown sympathy for the north's cause of preserving a united Yemen, said it had reservations about the position adopted in the statement. Since war broke out on May 4, the larger northern forces have pushed the southerners back from the pre-1990 north-south border into Aden itself, and Sanaa says it has taken the south's second port of Mukalla 620 kilometers by road east of Aden. One Western diplomat in Dubai said: "It looks like curtains for the southerners. Unless there is quick and effective foreign intervention, they stand little chance of halting the northern advance." Aircraft of southern Yemen's air force escaped from Mukalla's al-Rayan airport before it was captured by northern troops and were continuing the air war from a new base, a diplomatic source in the northern capital Sanaa said Wednesday. The source said no southern planes were captured at Rayan and southern aircraft attacked the airport Tuesday after it was in northern hands. Residents said northern forces appeared to be in control of the area commanding the approaches to central Aden. There was no immediate word on casualties, but residents said dozens of people were killed or wounded. They said that as soon as the fighting stopped in Mansoura and Sheikh Othman, northern trucks distributed food and drink to the hungry and parched people of the districts, while loudspeakers called on residents not to panic.