Mutassim, the fourth son of Libya' s fallen leader Muammar Gaddafi, was captured by fighters of the ruling National Transitional Council (NTC) on Wednesday in Sirte, a senior NTC defense official told Xinhua.

Mutassim Kadhafi, a son of Libya's former leader, has been arrested in his hometown of Sirte, the new National Transitional Council said on October 12, 2011. [Xinhua]

The capture was made several hours ago in Gaddafi's hometown, Mohamed Taynaz said.

In late September, the NTC has predicted that Mutassim, a national security advisor under Gaddafi's rule, was holed up in Sirte, while his brother Seif al-Islam was in Bani Walid. Sirte and Bani Walid are among a couple of redoubts of the fallen leader.

Meanwhile, Taynaz told Xinhua that Sirte is now fully controlled by the NTC fighters who are making efforts to get rid of some pockets of Gaddafi loyalists.

"The liberation of Sirte" may be announced in the following 24 hours, said the defense official.

Prolonged battles in Sirte witnessed upsurge in the previous days as the NTC intensified attacks on the city downtown and managed to take control of a conference hall in which pro-Gaddafi forces had stationed, a police headquarters, as well as a university at the main entrance to southeastern Sirte.

On Tuesday, NTC Chairman Mustafa Abdel-Jalil paid a visit to Sirte, where he told reporters that the ruling authorities would need two more days to fully control Sirte.

However, the NTC forces have said what they fear is that the Gaddafi loyalists would try to mingle with civilians and NTC fighters to escape the town.

Meanwhile, on Bani Walid, Taynaz said that the NTC is ready to launch the final attacks on the town, which has been considered difficult in geography as it is "between the mountains."