THE long-troubled Central African Republic is drifting deeper into crisis under an unruly band of rebels whose coup in March ended President François Bozizé’s decade of rule. Seleka, the rebel alliance, is struggling with dissent in its ranks, has gravely abused human rights and has aroused tension between Christians and Muslims. Humanitarian groups are calling for a more robust international intervention to help supervise and support a transition. But with Western governments engaged elsewhere and the African Union wary of tackling the CAR on its own, chaos is likely to persist.

A swift offensive beginning in December last year brought Seleka—a ragbag of factions meaning “the alliance” in a local language, Sango—to the doorstep of the capital, Bangui. It accused Mr Bozizé of breaching the terms of peace deals that had been struck in 2007 and 2008. In January in Libreville, the capital of nearby Gabon, a three-year power-sharing arrangement was agreed to in a last-ditch effort to prevent a coup. But Mr Bozizé refused to take it seriously. This prompted Seleka to take over Bangui on March 24th, killing 13 of the South African troops who were supposed to be holding the ring. Mr Bozizé fled.

The violence since then has displaced as many as 180,000 people within the CAR and forced many others to flee abroad. “People have been hiding in the bush,” says an aid worker in Bangui. “The priority has been to help people with food, medicine and essential household items. But we can’t reach all parts of the country.” This year’s harvest has been poor. The UN says less than a third of the $139m promised in humanitarian aid has been delivered. Some fear that a catastrophe looms.

The more remote bits of the CAR, such as the Vakaga area that abuts Chad and Sudan at the country’s northern point, have long been a haven for assorted guerrillas, including Uganda’s Lord’s Resistance Army, and sundry smugglers of weapons, diamonds and ivory. Last month the CAR was suspended from the club of countries that accept the Kimberley Process, a scheme to halt the trade in illicit diamonds that help fuel wars.

A contingent of troops under the aegis of the ten-member Economic Community of Central African States is meant to bring a measure of security to the CAR and persuade the rebels to honour the Libreville agreement that called for their disarmament, demobilisation and absorption into a reformed army. But it is too weak to achieve those laudable aims. It needs bolstering by the UN, the African Union and the former colonial power, France, which has been too busy in Mali to pay much attention to the CAR. Unless security improves, it will be impossible to hold a decent election, as the agreement stipulates. The International Crisis Group, a think-tank in Brussels, fears that the CAR may become a “grey zone at the heart of the continent”.