Eighteen people were killed and 21 others injured when members of the Boko Haram terror group attacked Nigeria's northeastern town of Damasak earlier this week, wreaking havoc in the area, a top official said.Babagana Umara Zulum, governor of the restive state of Borno, told reporters on Friday during he confirmed the toll from Tuesday's attack during a visit to Damasak, reports Xinhua news agency."The UN humanitarian hub, private residential houses, a police station, a primary healthcare centre were among properties destroyed," said Zulum.He said he visited Damasak to fully assess the extent of damage and interact well with security officials involved in the counter-insurgency operations in the town, adding measures were put in place to forestall future attacks.Boko Haram has been trying to establish an Islamist state in northeastern Nigeria since 2009.The terror group has also extended its attacks to other countries in the Lake Chad Basin.