At least three people were killed and 81 others wounded when a huge explosion shook one of the arms depots of the Syrian army in the central city of Homs on Thursday afternoon, pro-government Sham FM radio reported.

Several rockets slammed a number of areas in the southern districts of Wadi al-Dahab and al-Zahra in Homs city and caused a huge explosion in one of the arms depots of the Syrian army, the report said.

The attack was carried out by rebel groups and left huge material losses, it added.

Meanwhile, pro-government al-Ekhbaria TV cited a military source as denying media reports that the attack killed 40 people.

Activists' networks said the blast occurred at one of the Syrian troops' arms depots in the Wadi al-Dahab district in Homs city.

Moreover, other activists' websites posted video footage on the internet that shows a huge fireball spiraling into the sky with heavy black smoke surrounding it.

The attack comes as the Syrian administration is celebrating the army's 68th anniversary.

Syrian President Bashar al-Assad on Thursday stressed his confidence in winning the conflict with the rebels that have engulfed Syria for over 28 months.