CNN(CNN) -- Several al Qaeda "big fish" were among the 15 terrorists killed and seven captured in a series of gun battles and raids in and near Riyadh since Sunday, Saudi security officials say.
Sources in the Saudi government have said four of those killed or caught were on the list of 26 most-wanted terrorists, leaving just two of those on the list still at large.
The Saudi Interior Ministry is expected to announce DNA test results Wednesday afternoon to confirm the identities of the suspected al Qaeda militants killed and captured during a three-day stand-off and gun battle northwest of Riyadh and another gun battle Wednesday morning in an industrial area in southern Riyadh.
Several Saudi sources told CNN that Abdul-Rahman Mohammed Mohammed Yazji, one of the 26 most-wanted, was killed in the Wednesday morning gun battle.
The sources would not confirm or deny reports that Saleh Oufi, head of al Qaeda in the Arab peninsula, was seriously wounded and captured in that battle. He is also on the list of 26.
Investigators were also trying to determine whether two senior al Qaeda figures -- the suspected leader of the Islamic terror group in Saudi Arabia and a man linked to the March 2004 Madrid train bombings -- were among 14 militants killed in a battle that began Sunday and ended Tuesday, said Brig. Mansour Turki, an Interior Ministry spokesman.
Five militants were wounded and captured, and one surrendered, he said.
"We managed to capture really important fish," a senior Interior Ministry official told CNN.
The siege began Sunday in the Saudi city of al-Ras, about 350 kilometers (220 miles) from the Saudi capital. The city is located in the province of al-Qasim, considered the heartland of the conservative Islamic Wahabi doctrine.
DNA tests are being conducted to determine whether two of the bodies are those of Saud Humud al-Utaibi and Abd al-Karim el-Mejjati, two of the most-wanted al Qaeda suspects in the kingdom.
Al-Utaibi is believed to be the leader of al Qaeda in Saudi Arabia, having laid claim to that role in November 2004.
Investigators say el-Mejjati, a Moroccan explosives expert, is suspecting of helping plan the Madrid train bombings that killed 191 people and the May 2003 bombings in Casablanca, Morocco, that left more than 40 dead.