* Gunfire and arrests as ballot boxes snatched
* State governors wield great influence
* Hundreds killed in election violence last week
(Adds details throughout)
By Nick Tattersall
UYO, Nigeria, April 26 Ballot box snatching and thuggery marred state governorship elections in parts of Nigeria on Tuesday, although there was little of the orchestrated mob violence which has undermined similar votes in the past.
The state governorship races are the last stage of an election process so far deemed by observers and many Nigerians to have been the fairest in decades, but which has also seen some of the country's worst political violence for years.
Rioting left hundreds dead in the mostly Muslim north last week after President Goodluck Jonathan, a southern Christian, beat northern rival Muhammadu Buhari in presidential polls.
There were localised problems on Tuesday but nothing on a similar scale. Soldiers arrested people stealing ballot boxes in several states around the country, including parts of the oil-producing Niger Delta in the south and Kano in the north.
Security forces shot dead one man accused of trying to steal a ballot box in the northeastern city of Maiduguri, while witnesses reported gunfire as ballot boxes were snatched in at least one polling unit in the southern state of Akwa Ibom.
"There have been some disturbances and abuses across the country which are a concern ... voter turnout has been quite low in a lot of areas," said Clement Nwankwo, head of Nigeria's Policy and Legal Advocacy Centre.
The opposition candidate in Akwa Ibom, one of the fiercest races, said there had been widespread rigging there.
"This is not an election, this is not the voice of the people, it doesn't represent anything other than criminality," said James Akpanudoedehe of the Action Congress of Nigeria (ACN), calling for a partial cancellation of the vote.
Voter numbers were down, particularly in some northern areas hit hard by last week's riots, while accreditation started late in many parts of the country after hundreds of youth corp members, graduates on national service helping run polling units, stayed away fearing they may be targets of violence.
There were also far fewer international observers than for the presidential vote because of a delay in the election cycle.
The Independent National Electoral Commission (INEC), which delayed the polls by two days in the northern states of Kaduna and Bauchi, where last week's post-election violence was at its worst, said it was aware of the reports of problems.
"Where there are gross irregularities the commission has powers, including if necessary the cancellation of results at polling units," INEC spokesman Kayode Idowu said, but added there had been fewer incidents of violence than in the past.
Graphic on elections: link.reuters.com/xet78r
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State polls have often been the most volatile in Nigeria.
The 36 governors are among the country's most powerful politicians, wielding national influence and controlling budgets often larger than those of small African nations.
They are also seen as more likely to be able to influence the lives of ordinary Nigerians than the president, far away in the capital Abuja, meaning voters also see the stakes as high.
"It determines who governs the soul of your state," said Tony Effiong, 28, a student voting in Akwa Ibom's capital Uyo. "Everybody wants their voice to be heard and they believe that their governor is closer to them than the president."
Supporters in the commercial hub Lagos tried to boost voter turnout with chain text messages urging the recipients not to "sit in your house" and to remember "every vote is important."
This month's elections have been an emotional rollercoaster for the 73 million registered voters in Nigeria, which -- until 10 days ago -- had failed to hold a single credible election since the end of military rule in 1999.
Euphoria over a presidential vote deemed free and fair by observers turned to despair last week as Buhari rejected the outcome and his supporters took to the streets, burning churches, mosques and homes. Tens of thousands of people are still sheltering in army barracks.
Jonathan's People's Democratic Party saw its parliament majority narrow in this month's polls and is also expected to lose some states in Tuesday's vote. Buhari's Congress for Progressive Change is expected to perform strongly in the north. (Additional reporting by Austin Ekeinde in Uyo, Samuel Tife in Yenagoa, Mike Oboh in Kano, Ibrahim Mshelizza in Maiduguri, Oludare Mayowa and Joe Penney in Lagos, Shuaibu Mohammed in Jos, Anamesere Igboeroteonwu in Onitsha; Writing by Joe Brock; editing by James Jukwey and Maria Golovnina) (For full Reuters Africa coverage and to have your say on the top issues, visit: af.reuters.com/ )