"Three blasts have taken place ... in a high school, there are some casualties to our Shia people," said Khalid Zadran, the spokesman for Kabul's commander.
The site of the explosion was reportedly used by the Amal Movement to store ammunition and weapons.
The blast was the second in a week in the Afghan capital, after another tore through the main money exchange center, killing one person and injuring dozens.
The country's emergency services were called to the club at 3 a.m. (2300 GMT on Saturday) and extinguished the fire before it could spread, the AP said, citing a statement from the department.
About 70 people were injured after Russian missiles hit Okhtyrka. Russian forces are becoming increasingly frustrated.
The book dissects the horrors after Hezbollah explosives destroyed much of the city.
Another man suffering from injuries to his chest and limbs was evacuated him to a hospital in fair and stable condition.
Unidentified assailants stabbed and wounded the store owner four days prior to the attack.
Judge Tarek Bitar's investigation into the massive blast, which killed more than 215 people and deepened Lebanon's economic crisis, has been suspended repeatedly by lawsuits from senior politicians.
Initial reports suggested no mass casualties on the main island of Togatapu, but two people were reported missing and the capital Nuku'alofa was badly damaged.