From CNN:

The attack began around 5 p.m. when a car bomb exploded at the hotel’s entrance, according to witness Aden Hussein, who said he was meters away from the hotel when the blast happened.

Gunmen then went inside the hotel, shooting people, Hussein said.

One of the attackers, wearing a belt with explosives, blew himself up inside the hotel, police Capt. Ahmed Abdi said

A few hours after the assault began, state-run media reported that security forces stormed the building and killed the remaining assailants.