However, it was unclear how many fighters and weapons the defeated alliance had, and many of the U.S.-backed warlords remain in hiding.

The threat was issued a day after Islamic fighters stopped showings of the World Cup soccer tournament, one of the first signs that the fundamentalist force now controlling nearly all of southern Somalia could install strict Islamic rule.

Muse Sudi Yalahow said his group of secular warlords is regrouping to fight the Islamic militia, whom he accused of having ties to al-Qaida. U.S. officials have said they supported the warlords’ fight against Islamic leaders sheltering three al-Qaida leaders indicted in the 1998 U.S. Embassy bombings in Kenya and Tanzania.

“The alliance will continue fighting until we win the war on terror. We will hand down the terrorists linked to al-Qaida,” Yalahow said. “We will never surrender our arms.”

The state of the secular alliance and how many weapons it has is not clear. Many members are in hiding after weeks of fighting with the Islamic militia killed at least 330, many of them civilians. Its leader was thought to be in Ethiopia seeking reinforcements.

Two were wounded Saturday as the militia, which is controlled by a group of religious court leaders, broke up World Cup viewing parties by firing in the air and cutting electricity to theaters. The vice chairman of the Islamic Courts Union, Sheikh Abdukadir Ali Omar, said that was a way to prevent “corrupting the children in this Muslim community.”

The Islamic Courts Union is a fragile alliance of radical and moderate Muslim groups from different clans. On Saturday, its leader denied that he wanted to impose a Taliban-style government and said, “We will accept the views of the Somali people.”

Sheikh Sharif Sheikh Ahmed said no one in his organization had connections to al-Qaida.

“American concerns are based on misconception,” he said. “They used to take information from warlords. … Islamic courts do not harbor foreign terrorists.”

But the episode left some residents wondering if the semblance of security that has returned to the city under the Islamic militia will come with a price.

“As soon as the Islamists took over the security of our city, we thought we would get freedom,” said Adam Hashi-Ali, a teenager in Mogadishu. “But now they have been preventing us from watching the World Cup.”