May 20th 2014, 7:30 by C.B. | BAMAKO
ON May 16th, as the showers known as mango rains arrived, Mali's new prime minister, Moussa Mara, announced that he would tour Timbuktu, Kidal and Gao. These are the northern cities that fell to separatists and hard-line islamists in 2012, provoking a coup and then France's successful intervention. Two years later, Timbuktu and Gao have seen something of a return to normalcy, but Kidal is still tense. The tiny town sits in a lawless desert region. One loud criticism of Mali's new government is that little has been done to tame armed groups, perhaps through peace talks. Mr Mara's visit might have been a positive sign.
But it turned out to be nothing of the kind. Kidal's runway was temporarily blocked by protesters. A bomb was discovered and disarmed. Shortly after Mr Mara's arrival from Timbuktu, a firefight flared up. By the day's end, the governor's office had been burned, up to 30 civil servants kidnapped by militants and Mr Mara evacuated by the UN. Dozens were killed including Malian soldiers, civil servants and separatist fighters. On his safe return to Bamako, the capital, Mr Mara called the attack a "declaration of war".
The country's main rains are supposed to start in June, and judging their timing correctly can mean the difference between a bumper crop and famine for farmers. As for Mr Mara, the question is whether a rough first two months will jolt him to rethink his plan for cultivating the north.