Lagos - A video clip apparently showing the traditional ruler of Lagos snubbing the spiritual leader of the Yoruba people has caused controversy in Nigeria.In the footage, the 73-year-old Oba (king) of Lagos, Rilwan Akiolu, appears to rebuff the greetings of the Ooni of Ife, Adeyeye Enitan Ogunwusi, at a public event in the city on Tuesday. The ooni, 42, then went quietly to his seat without incident but what appeared to be the oba's dismissive attitude sparked protests online - and speculation as to what was behind it.The Ooni of Ife is the most powerful and influential monarch among the Yoruba people of southwest Nigeria, who are the country's second biggest ethnic group after the Hausa-Fulani.Historically, the ooni or any king in Yorubaland was revered and considered "the sovereign, second in rank to the gods"."We want to assume that Oba Akinolu did not realise it was the ooni that greeted him," Yinka Odumakin, of the pan-Yoruba socio-cultural group Afenifere, told AFP. "Otherwise, we would regard what happened as a sacrilege and an abomination to Yoruba culture. "It's a taboo that any Yoruba oba would disrespect the ooni in that manner. It's not acceptable and is utterly condemnable."The powers of the Yoruba kings and other traditional rulers were reduced under British colonial rule and their role is now largely ceremonial.But they are regarded as custodians of culture and still wield influence on their people in local matters.Ogunwusi, from one of the ruling houses in the Ife kingdom, was installed as the 51st ooni in December 2015, succeeding Okunade Sijuade, who ruled for 35 years until his death.Before that he made millions as an entrepreneur in real estate and marketing.Moses Olafare, the ooni's spokesperson at his palace in Ile-Ife, said the monarch "has no issues with the Oba of Lagos"."He is not involved in any rivalry or supremacy contest with any oba in Yorubaland," he added."His mission since he was crowned has been to bring about peace, unity and progress to Yorubaland. He remains very focused and undeterred in this task. "He has visited Oba Akinolu twice since he became king but for reasons best known to him, Oba Akinolu has not deemed it fit to replicate the visit."No-one at the oba's palace was immediately available to comment.