(SomaliNet) An explosion of grenade bomb in the port town of Bosaso in the semi autonomous region of Puntland, northeast Somalia has left seven people wounded overnight, witnesses said on Friday. According to residents, unknown militants hurled a grenade bomb into a house where local elders had a meeting in Biyo-Kulule village in Bosaso on Thursday night. The blast caused the injuries of seven people including those were meeting. The attackers escaped unharmed as the residents grew more concern over what happened. No group has claimed the responsibility for the latest bomb attack so far and it is not clear whether this bomb related to the recent acts of kidnappings in Puntland. Shortly after the explosion, the security forces sealed off the area and began investigation over who might be responsible for it.