Explosions ripped through a three-story building on Friday in southern Lebanon that might have been used to store weapons by the militant group Hezbollah, Lebanese security officials said.

At least five people sustained various wounds and burns and were rushed in for treatment, according to Lebanese security and hospital sources.

Open gallery view Young Hezbollah supporters holding mock ups of Katyusha rockets in front of a portrait of group leader Sheikh Hassan Nasrallah. Credit: AP

According to a witness, the sounds of further blasts continued to be heard in the Hezbollah-dominated town of Shehabiyeh as ambulances and firefighters scrambled to the site of the initial explosion.

Lebanese army troops are said to have cordoned off all areas leading to the village.

Shehabiyeh, near the city of Tyre, is located in the volatile border zone south of the Litani River in which Hezbollah has been banned from having weapons under a United Nations resolution that ended the 2006 war between the militant group and Israel.

The area is patrolled by UN troops and Lebanese soldiers and has been largely peaceful since the war, but there have been a number of mysterious explosions in the past year at buildings suspected of housing Hezbollah arms caches.

It was not clear what caused Friday's blasts, but one official said it might have been triggered by an electrical short circuit setting off secret Hezbollah munitions.

In July 2009, an explosion at a Hezbollah arms depot near Tyre killed a number of people and brought attention to Hezbollah's stockpiling of weapons in south Lebanon.

UN Resolution 1701 prohibits Hezbollah from engaging in military activities in south Lebanon and forbids weapon smuggling to the group.

Two months ago, the Israel Defense Forces published evidence of alleged Hezbollah military activity in south Lebanon.