An International Committee of the Red Cross (search) worker who had disappeared in the warring Russian republic of Chechnya has returned home, a Red Cross spokeswoman said Sunday, as media reports indicated that security force detained a prominent Chechen separatist.

Spokeswoman Anastasia Isyuk said Said-Khusein Deniyev, who disappeared on Thursday after leaving the organization's office in the Chechen capital Grozny (search), had come back home, and that his relatives said he was in normal condition.

Chechnya (search), where separatist rebels have been fighting Russian forces for more than five years, is beset by abductions and disappearances, some blamed on the insurgents and others on security forces.

Rudnik Dudayev, the security chief in the Moscow-appointed Chechen administration, said Sunday that about 500 people were kidnapped in Chechnya last year and most of them have remained missing, the ITAR-Tass news agency reported. He said that the number of abductions rose by some 50 percent last year compared to 2003.

Another 12 people have been abducted since the year's start, Dudayev said.

Russian forces pulled out of Chechnya after the first, 20-month war in 1994-1996, leaving the region de-facto independent. They rolled back in September 1999 after Chechnya-based rebels raided a neighboring province and after a series of apartment building explosions blamed on the rebels.

The federal troops quickly overran most of Chechnya, but rebels have continued resistance, staging daily raids and landmine explosions and launching deadly terror attacks outside the region, like September's school seizure in the city of Beslan that killed over 330 people.

The NTV television reported Sunday that Vakha Arsanov, a prominent separatist leader, had been detained by pro-Moscow Chechen security forces in Grozny.

Warlord Shamil Basayev, who claimed responsibility for the Beslan attack, remains at large along with rebel chief Aslan Maskhadov.