Hundreds of Somali insurgents loyal to Islamist group al-Shabab have poured into Mogadishu, witnesses say, amid expectations of a major battle. Eyewitnesses reported that fighters, about 20 vehicles and artillery had arrived in Somalia's capital overnight. Residents have been fleeing for days amid a widespread belief that the rebels and government forces are on the cusp of a serious showdown. Al-Shabab and other rebel groups control much of southern Somalia. However, the government has recently promised to launch an offensive to take control of the country. The BBC's Mohamed Olad Hassan, who is in Mogadishu, says the rebels have promised to resist the government. He says the war propaganda from both sides has spread fear throughout the city. Wracked by violence As he fled his home, father-of-three Mohamed Isa Abdullahi told the AFP news agency neither side in the conflict cared about civilians. "The government has vowed to retake the city, rebels are going to stick to their bastions and the civilians are going to be the only victims, as always bearing the brunt of the war," said the 39-year-old. Gunfights and shelling are common in the city - and civilians are killed by both sides. The transitional government - backed by African Union troops and UN funds - controls only a small part of the capital. The rest of the country is ruled by warlords, al-Shabab or other Islamist militias. Somalia has been wracked by violence for much of the past 20 years. It has not had a functioning central government since 1991. Source: BBC