(Updates with details and quote) ABUJA, April 21 (Reuters) - A petrol tanker laden with gas detonators heading towards Nigeria's electoral headquarters stopped short of its target and failed to explode on Saturday, hours before voting was due to start in presidential elections. The attempted arson attack in the capital Abuja came hours after militants in the southern oil region stormed the office of the ruling party's vice-presidential candidate in what police said was an attempt to kill him and abort the election. "A tanker fully loaded with substance yet to be fully identified attempted to burn down INEC headquarters in Maitama, Abuja. The tanker was unmanned," police chief Sunday Ehindero said, referring to the Independent National Electoral Commission. "The vehicle was stopped by the electrical pole and barriers at the entrance to the INEC office. The vehicle was on fire... The tanker had gas cylinders which would have served as explosives if the fire had not been put out," he added. Ehindero called on Nigerians to go ahead and vote.
