The TVGE channel broadcast footage of wrecked and burning buildings after the four explosions ravaged the Nkoa Ntoma camp in the economic capital Bata and the surrounding neighbourhoods.

People -- including children -- were seen being pulled from the rubble and the wounded lying on a hospital floor, while a column of thick black smoke rose from the military site.

The explosions were caused by "an accident due to the negligence of the unit in charge of storing explosives, dynamite and ammunition", Obiang Nguema said in a statement read on state television.

His jet-setter son, Teodoro Nguema Obiang Mangue, vice president with responsibility for defence and security, appeared in the television footage at the scene of the blasts inspecting the damage, accompanied by his Israeli bodyguards.

Teodorin, as he is known, is increasingly seen as the president's designated successor.

The camp, where the first explosion struck in the early afternoon, houses among others elements of the army's special forces and the paramilitary gendarmerie, according to a journalist with TVGE.

Spain, the former colonial power in Equatorial Guinea, urged its citizens via its Malabo embassy to stay at home following the explosions.

Bata is the largest city in the oil- and gas-rich central African nation, with around 800,000 of the nation's 1.4 million population living there -- most of them in poverty.

While it sits on the mainland, the capital Malabo is on Bioko, one of the country's islands off the west African coast.

Equatorial Guinea has been ruled by 78-year-old Obiang Nguema for nearly 42 years.

In December last year the UN's top court found in favour of France in a bitter battle over a swanky Paris property seized in a corruption probe into his son Teodorin.

Opposition figures and international organisations regularly accuse Obiang Nguema of committing human rights abuses.

The authoritarian leader has seen off at least half a dozen assassination or coup attempts to become Africa's longest-serving leader.

Malabo claimed to have foiled a coup plot in December 2017 for which 130 people were sentenced to prison terms ranging from three to 96 years, half of them in absentia.

They included five French nationals as well as citizens of Chad, the Central African Republic and Cameroon.