The United Nations refugee agency today raised a new alarm over the number of Colombians driven from their homes by clashes between Government forces and irregular armed groups in the north-eastern Catatumbo region of a country where more than four decades of war have already displaced at least 2.5 million people. “Since the start of the year, around 2,000 people from Catatumbo have registered with the authorities as forcibly displaced, but this could be only the tip of the iceberg,” UN High Commissioner for Refugees (UNHCR) spokesman Ron Redmond told a news briefing in Geneva. The exact numbers are hard to pin down because many have not registered with the authorities or UNHCR. The government has sent an extra 27,000 troops to the region and clashes with irregular armed groups are frequent.Villages have emptied out as more people flee in the region close to the Venezuelan border, where some of the worst violence and human rights violations in Colombia’s long and bitter conflict have occurred.La Victoria is a ghost town. The last inhabitants fled last month when members of an irregular armed group executed two of the village’s young men in broad daylight. The neighbouring community of El Diamante also quickly emptied out.The 1999 massacre in La Gabarra, in which some 40 people were killed by members of an irregular armed group, remains one of the bloodiest single incidents against civilians in Colombia’s recent history. Another massacre two years ago left 34 coca farmers dead in the same hamlet.The volatile security situation is made worse by the illegal cultivation of coca, the raw product for cocaine, with some of the irregular armed groups fiercely resisting government attempts to eradicate their plantations.Many displaced people hesitate to register. Some are traumatized and very scared, and many do not want to talk about what has happened to them. It can also take a very long time to be officially recognized as an internally displaced person, and some people get discouraged.“Unfortunately, this means that they miss out on the protection and assistance that registration entitles them to,” Mr. Redmond said. With its 2.5 million internally displaced people, Colombia is now the country with the largest population of concern to UNHCR in the world.