U.N. attack helicopters hit rebels in eastern Congo U.N. attack helicopters hit rebels in eastern Congo - Africa By Jonny Hogg KINSHASA (Reuters) - United Nations attack helicopters hit rebel positions in eastern Congo on Saturday after insurgents gained ground in heavy fighting with government troops, the U.N. said. The clashes to the south of the town Kibumba mean the rebels have advanced to within 30 km (18 miles) of Goma, the closest they have been to North Kivu's provincial capital since a rebellion exploded in the eastern provinces eight months ago. North Kivu governor Julien Paluku said the army retreated to the southern outskirts of the town after M23 rebels - a group of soldiers who mutinied in April - advanced with support from neighbouring Rwanda. A Congolese government statement claimed 4,000 Rwandans had crossed the border. Rwanda rejected the accusations, the latest in a string of charges by the Congolese government in Kinshasa. The Rwandan government called on Congo's army and the rebels to halt the fighting as shells were landing in its territory. The French mission at the United Nations in New York said it had called for an emergency meeting at the Security Council on the situation in Congo for 2000 GMT on Saturday. More than five million people are estimated to have died from violence, hunger and disease in wars in Congo since 1998. It is the deadliest conflict since World War Two. U.N. experts have said in reports they have evidence that Rwanda has supported the M23 rebels in eastern Congo. They have called on the Security Council to impose sanctions on Rwandan officials in response. "The Rwandan army came across the border behind our troops, that's why our troops withdrew," Paluku told Reuters by telephone. "The (rebels) are just a few kilometres away, so of course Goma is under threat, we can't hide that," he said, adding that government troops were regrouping at Kilimanyoka, 12 km north of the city. Rebels said they had no immediate plans to attack Goma. The U.N. peace keeping mission in Congo said army units had come under heavy weapons fire since early on Saturday morning, forcing civilians to flee. U.N. attack helicopters were dispatched to strike rebel positions south of Kibumba. "So far ten missions have been carried out by our attack helicopters," the U.N. said in a statement. The U.N. has a mandate to protect civilians and support government troops when they need it. No casualty figures have been given by any force. Rwanda's army has repeatedly sent soldiers into Congo during nearly two decades of conflict in Africa's Great Lakes region but Kigali has strongly denied Congolese and U.N. accusations of support for the M23. These are absolutely false allegations. They are very tired, and very old. Whenever DRC (the Democratic Republic of Congo) is defeated on the battlefield it's meant to be (Rwanda's army)," Rwandan army spokesman Brigadier General Joseph Nzabamwita told Reuters. Rwanda has called on (Congo's army) and M23 to stop this useless war ... Rwanda is being violated by constant bomb shells on our territory," he added. More than three-quarters of a million people have fled their homes since the fighting began, and regional efforts to find a solution have so far failed. M23 spokesman Vianney Kazarama told Reuters the rebels were now in control of Kibumba but said they would not advance further. "We're stopping here, we're waiting, we're not going to Goma," he said, reiterating a call for the government to start negotiations. Additional reporting by Jenny Clover in Kigali, Louis Charbonneau in New York; Writing by David Lewis, editing by Rosalind Russell