More than 5,000 people gathered for an anti-Ethiopia protest in the capital Monday, days after troops from neighboring Ethiopia arrived to protect Somalia's virtually powerless government from Islamic militants. The protesters, who packed a stadium in northern Mogadishu, burned an Ethiopian flag and carried signs that said, "We Must Fight Them!" Ethiopia, a largely Christian country, is the traditional enemy of Somalia, which is mostly Muslim. The protest was organized by an Islamic militia that is accused of links to al-Qaida and has seized control of the capital and much of southern Somalia. The government holds only one town, is militarily weak, undermined by internal rivalries and includes warlords accused of dragging the country into anarchy. Ethiopian and Somali government officials have denied Ethiopian troops are in the country, but Somali witnesses in several towns reported seeing them cross from Ethiopia four days ago and go first to Baidoa, the only town held by the government, and then to nearby Wajid. Solomon Abebe, spokesman for the Ethiopian Ministry of Foreign Affairs, refused to address the witness accounts Monday, but lashed out at the Islamic militia's leader, calling Sheik Hassan Dahir Aweys "scum" and a terrorist. Somali government leaders may be reluctant to acknowledge that Ethiopian troops have come to their aid because they do not want to appear to be beholden to the country's traditional adversary. Anti-Ethiopian sentiment still runs high here. "The Ethiopians have denied the occupation in our land, but we shall show the world corpses or POWs from their ranks," Sheik Muqtar Robow, deputy defense chief for the Islamic group, said during the protest in Mogadishu. On Sunday, a top Islamic leader, Sheik Sharif Sheik Ahmed said: "I call on Somalis to be ready for a holy war against an invasion from the enemy of the religion and the country." Ethiopia's move could give the internationally recognized Somali government its only chance of curbing the Islamic militia's increasing power. But the incursion could also be the pretext the militiamen need to build public support for a guerrilla war. Somalia has not had an effective central government for 15 years since warlords overthrew dictator Mohamed Siad Barre in 1991 and then turned on each other. Some of those warlords now sit on the transitional government. Earlier Monday, a Somali warlord and 150 of his militiamen offered their support to the government. Mohamed Qanyare Afrah arrived in the central town of Baidoa, the seat of President Abdullahi Yusuf's government, at 4:30 a.m. (0130 GMT), said Mohamed Dooli, one of Qanyare's militia commanders. Qanyare was among a group of secular warlords and their allies who fought the Islamic militia for control of Mogadishu between February and June in battles that killed 400 civilians, according to a report Sunday from a Somali human rights group. The secular warlords, who had been backed by the US, were routed and Qanyare retreated to his home village in central Somalia, where Islamic militia pursued him to try and force him to surrender his weapons, Dooli said. Qanyare was able to reach Baidoa, 240 kilometers (150 miles) northwest of Mogadishu, with eight pickups mounted with machine-guns, the main mobile weapon in Somalia. Prime Minister Ali Mohamed Gedi had fired Qanyare from the Cabinet because he had waged his war on the Islamic group independently of the government. But Monday, Qanyare, the former national security minister, was welcomed by members of the transitional parliament and local administrators, Dooli said. He was scheduled to meet with Yusuf, Gedi and the speaker of parliament later Monday. Qanyare and his group are believed to have bought their arms from Ethiopia, though this has never been officially acknowledged by either the warlords or Ethiopia. Farah Yaire, a resident of Wajid, where 200 Ethiopian soldiers moved in Saturday, said that an Ethiopian military helicopter has been landing from neighboring Ethiopia every day and taking off. Yaire, who lives near the airport, did not know what the helicopter was carrying because the airport is closed to civilians.