MOGADISHU - Somali authorities announced a nightime curfew in the central town of Baidoa on Sunday after a grenade attack on a bank, killing a security guard, the second such attack in four days. ‘After realising that people are causing insecurity and chaos here, we have decided to impose a curfew on Baidoa for a week, from 9:00 pm (1800 GMT) to dawn,’ Ibrahim Hashi Gabo, Baidoa police chief, told a press conference.Sunday’s attack in the town, about 250 kilometres (155 miles) northwest of the capital Mogadishu, left one bank security guard dead and three other people injured, police official Adan Bid told AFP. Government forces sealed off the area after the suspected assailant fled the scene. ‘We are investigating the matter, but it seems that this grenade explosion is linked to terrorist actions that are taking place in the country,’ Bid said.