By Lanre Ola MAIDUGURI, Nigeria (Reuters) - Boko Haram insurgents attacked the outskirts of Maiduguri in northeast Nigeria on Sunday, security sources said, their second assault in a week on a city they hope to make the capital of a breakaway Islamist state. The insurgents, who arrived in several armed pick-up trucks and on motorbikes, attacked three places in the south of Maiduguri at around the same time, a security source said. In a separate incident in the town of Potiskum, 230 km (140 miles) west of Maiduguri, a suicide bomber blew himself up outside the house of federal legislator Sabo Garbu, killing 10 people, two security sources told Reuters.