Via NBC News:

An apparent suicide bomber blew up a section of a Beirut hotel on Wednesday, killing two Lebanese security officers involved in a raid on the hotel in search of terrorists believed tied to Islamic State of Syrian and al-Sham (ISIS), officials said.

The explosion sent flames and a dark cloud of black smoke billowing out of the third-floor windows of the Duroy Hotel in the Raouche district, a well-heeled neighborhood that borders the Mediterranean Sea.

An official in the general security department told the Associated Press that security forces were raiding the hotel when the suspect on the fourth floor detonated explosives in his hotel room. The official spoke on condition of anonymity in line with regulations.

Damage appeared to be confined to the third and fourth floors of the hotel. The explosion started a fire on the third floor, and thick black smoke billowed above the hotel as fire engines struggled to contain the blaze.

Lebanese media reported that there may have been a second suspect in the hotel engaged in gun battles with authorities.