* Islamist opposition leader Turabi arrested
* Arrest comes one month after elections
* Security says he "summoned" for questioning
KHARTOUM, May 16 Sudanese security agents detained opposition party leader Hassan al-Turabi and seized a print-run of the movement's newspaper, supporters and family members said on Sunday.
Turabi, who was close to Sudan's President Omar Hassan al- Bashir before a bitter power struggle and split in 1999-2000, was arrested in his house late Saturday, a month after his Popular Congress Party (PCP) contested national elections.
"They went into the printing press and confiscated all the copies of the newspapers .... The whole issue of Rai Al-Shaab has been taken," Turabi's son Siddiq al-Turabi said on Sunday.
A security source told Reuters that Turabi had been summoned, possibly because of his alleged links to the Darfur rebel Justice and Equality Movement (JEM) which has clashed with government forces over the past week. Turabi denies any link.
Party member Kamal Omar told Reuters that Turabi, an Islamist ideologue who has been arrested several times since his split with the president, was taken to Khartoum's Kober prison.
PCP members said they were still waiting for an explanation of the late night arrest and were worried for the health of their 78-year-old leader.
"I condemn the arrest. It shows we are not heading towards democratic transformation," PCP presidential candidate Abdallah Nhial Deng said. "The government will bear the responsibility for any deterioration in his health."
A security source could not confirm the reasons behind the arrest but said it was "probably because of (links with) the Justice and Equality Movement."
"After he has answered some questions he will either be arrested (formally) or released," the source said.
Sudan's army on Saturday said it had ousted JEM, Darfur's most militarily powerful rebel group, from its stronghold near the border with Chad, killing 108 insurgents.
JEM denied the report said it left the area days earlier to spare civilians and had dispersed its forces across Darfur and the neighbouring oil-producing state of South Kordofan.
The International Criminal Court issued an arrest warrant for Bashir last year for war crimes in Darfur, charges he denies. Mostly non-Arab rebels took up arms in 2003 accusing Khartoum of neglecting the arid region. Washington says Khartoum committed genocide during a brutal counter-insurgency campaign. (Reporting by Andrew Heavens and Opheera McDoom, editing by Paul Casciato)