KABUL: Afghan police seized 22 tonnes of explosives destined for use in suicide and roadside bombs, officials said Tuesday, four days before elections that Taliban insurgents have vowed to attack.

The explosives were uncovered in dozens of plastic-wrapped bags in the northern province of Takhar, as security forces ramp up efforts to protect candidates, election staff and voters.

“The national police have discovered a cache containing 22,220 kilogrammes of explosives used for making roadside bombs and (carrying out) suicide attacks,” a statement from the interior ministry said.

“The cache was discovered in a village outside Taloqan (Takhar's provincial capital).”A spokesman said investigations were underway to establish how the explosives were due to be deployed in Afghanistan.

The Afghan government has pledged to ensure a safe election, despite the gradual withdrawal of US-led Nato troops from the country.

National police and soldiers will provide security for the vote, though the Nato military coalition has said it will assist if necessary.

Saturday's vote will choose a successor to President Hamid Karzai in an election seen as a benchmark of progress since the Taliban were ousted from power in 2001.

Election offices in the capital, Kabul's most prestigious hotel and a guesthouse run by a US anti-landmine charity have all been targeted by insurgents in recent weeks.