Authorities said the explosions were caused by devices planted in the stores
Attack killed 30 soldiers and injured 70 others
Al-Shabab militant group claims responsibility for the attack in a statement on Telegram
All 30 passengers and four crew members survived, according to a statement
Connections were cut when ship severed undersea cable
Hassan Sheikh Mohamud says he wants to be elected so that he can 'complete the unfinished business'