Kano - Sierra Leone's deputy high commissioner has been snatched in Nigeria, government sources said Friday, the first kidnapping of a diplomat from the west African country in more than half a century.Alfred Nelson-Williams was taken as he was travelling by road from the Nigerian capital of Abuja north to attend a ceremony in Kaduna, a city around 200km away.Local security officials said they were still investigating how the kidnapping took place."We want to establish whether he had security escorts with him and what happened to them," Kaduna state security official Yusuf Yakubu Soja told AFP. "He was kidnapped on his way to Kaduna from Abuja to attend the passing out ceremony of military officers at the Armed Forces Command and Staff College in Jaji outside Kaduna."Sierra Leone's information minister Mohamed Bangura said the government was working with Nigerian authorities to secure Nelson-Williams' release.Neither he nor police could confirm whether the kidnappers had demanded a ransom.Kidnappings are common in Nigeria, where the rich and powerful drive bulletproof cars and even hire military and police chaperones as protection from highway bandits.Foreign ministry sources in Freetown told AFP that "this is the first time that a Sierra Leone diplomat has been kidnapped anywhere on posting since independence in 1961".The most sensational kidnapping in Nigeria's recent history saw 276 schoolgirls snatched from their classroom in the remote northeastern town of Chibok in April 2014 by Boko Haram jihadists. South AfricanThe government of former president Goodluck Jonathan was criticised for its slow response to acknowledge the kidnapping and for its inability to find and recover the girls.Late last month, popular musician Ado Dahiru Daukaka was also kidnapped in Nigeria's northeast Adamawa state and then freed days later, after releasing a scathing anti-graft song.But in the oil-producing delta region in the south, where wealthy Nigerians and expatriate workers are usually the target, abductions are often for financial gain.This week, two Indian workers were kidnapped on their way to work in central Benue state. The pair have yet to be released.Last week, three Australians, a New Zealander and a South African were kidnapped along with two Nigerians near the capital of Cross River state in the country's south. They were released four days later, but officials did not say whether the kidnappers received any ransom.