A key figure of al-Qaida in Iraq, accused of bombing a Shiite shrine in Samarra and killing an Iraqi female journalist, has been arrested by Iraqi security forces, a senior Iraqi official said on Wednesday.

"Iraqi security forces have arrested the terrorist a Tunisian national Yusri Fakhir Muhammed, also named Abu Qudama al-Tunisi, during a military operation in the Udhaim area in Diyala province northeast of Baghdad," said Muwafaq al-Rubaie, Iraq's National Security Advisor, told reporters.

The capture of Muhammed was another blow to al-Qaida in Iraq following the killing of its leader Abu Musab al-Zarqawi in a US air strike near Baquba, 65 km northeast of Baghdad, on June 7.

Al-Rubaie accused Tunisi of bombing the revered shrine of ImamAli al-Hadi in Samarra under the leadership of Haitham al-Badri, a provincial leader of al-Qaida in Salahudin province, who is still at large.

"He (Tunisi) took an active role under the leadership of Haitham al-Badri in blowing up the golden dome mosque of Samarra on the 22nd of February this year," al-Rubaie said.

He also accused Tunisi of killing well-known female Iraqi journalist Atwar Bahjat near Samarra, after she arrived near the city to cover the bombing of the shrine.

"Tunisi took part in the assassination of Atwar Bahjat while she was covering the bombing of the Ali al-Hadi and Hassan al-Askari mausoleum in Samarra after he received information about her place from Haitham al-Badri," al-Rubaie said.

Bahjat was an Iraqi journalist for the al-Arabiya television, who was abducted and brutally murdered while covering the Samarra bombing.

She had previously worked for the al-Jazeera television. In the aftermath of the 2003 Iraq War, she became one of the most familiar faces on the Arabic-language satellite television.

According to al-Rubaie, Tunisi was captured after he took part in an attack on an Iraqi army checkpoint in Dhuluiyah town, some 100 km north of Baghdad.

"They were trying to storm an Iraqi military checkpoint in al-Dhuluiyah," al-Rubaie said.

He said that Iraqi army and security forces have killed 15 foreign fighters and captured Abu Qudama al-Tunisi in an operation. Al-Rubaie said that Abu Qudama confessed to the bombing of the shrine in Samarra with a group of fighters including four Saudi fighters.

The shrine of Ali al-Hadi, or the al-Hadhrah al-Askariyah, contains two tombs of Ali al-Hadi, who died in 868 AD, and his son Hassan al-Askari who died in 874 AD.

The two were the 10th and the 11th of Shiite's twelve most revered Imams. Shiite pilgrims visit the shrine from all over the world.

(Xinhua News Agency June 29, 2006)