* Arrest is joint U.N.-Congo army action
* U.N.'s Wallstrom welcomes news
(Adds further details and reaction)
By Katrina Manson
GOMA, Democratic Republic of Congo, Oct 5 (Reuters) - U.N. peacekeepers captured on Tuesday a rebel commander they accuse of being behind the rape of hundreds of villagers in eastern Democratic Republic of Congo in August.
A U.N. report last month said a man it named only as "Colonel Mayele" led a coalition of militiamen that attacked the town of Luvungi on July 30 and held it until Aug. 3, raping at least 303 people.
"We have taken him and we have transferred him to the FARDC (Congo's national army)," a U.N. spokesman said by telephone, adding Mayele was taken from the bush.
The United Nations peacekeeping force MONUSCO -- the world's largest U.N. peacekeeping mission -- was criticized for failing to prevent the mass rape, which took place just 20 miles (30 km) from a U.N. base.
The high-profile arrest comes during a visit to Congo by the U.N.'s special representative on sexual violence, Margot Wallstrom, who has called Congo the rape capital of the world.
"Colonel Mayele" is from a militia named Mai Mai Cheka and led a coalition of rebel groups in eastern Congo.
"Let his apprehension be a signal to all perpetrators of sexual violence that impunity for these types of crimes is not accepted and that justice will prevail," Wallstrom said in a statement.
Dr Cris Baguma of International Medical Corps, who visited the attacked villages to help care for the injured women, also welcomed the capture.
"This is very good news -- now the second thing will be to make sure they keep him for a long time," he told Reuters.
"What horrified me so much is how systematic these rapes were. It is devastating that because of the security situation we did not get there in time -- within 72 hours -- to give them HIV and pregnancy prevention pills," Baguma said.
Baguma said more than 200 rebels had arrived saying they had come in peace and did not start raping until the women in the village had prepared food for them in celebration. Several men raped each victim, including children, men and old women.
The U.N. Security Council heard evidence last month that Mayele asserted that the rebels had arrived in peace with a rebel leader from the Rwandan Hutu FDLR, Colonel Serafim, before the rapes took place.
"Men saw how they raped their wives, sons saw how they raped their mothers: everyone in these villages is now very withdrawn and cold and in need of psychological assistance," said Baguma.
"At first many husbands did not reject their wives, but the men feel ridiculed and couples are starting to have problems."
Congo's eastern provinces are haunted by Rwandan Hutu FDLR insurgents and Mai Mai militia who have lingered in the vast and minerals rich zone since Congo's 1998-2003 war.
An official statement from MONUSCO said Mayele was taken in a joint action between MONUSCO and the FARDC in the Walikale district on Tuesday.
The statement added the FARDC's military prosecutor has opened a criminal investigation against him.