Media playback is unsupported on your device Media caption Explosives set off by US tree surgeon Jon Sterkel to celebrate his wife's pregnancy.

A US man who celebrated news that his wife was expecting a baby boy by setting off an explosion in Nebraska is facing police action which could result in a year in jail and a fine.

Tree surgeon Jon Sterkel told the BBC he used an explosive rifle target which sent blue smoke billowing into the air.

The blast was reportedly so loud that it was heard nearly 5km (3 miles) away.

Mr Sterkel has apologised after causing a police alert. He said that he was not aware his actions were illegal.

"The explosives I bought are readily available in most department stores, and even most law enforcers I have spoken to are not aware that they are illegal," he told the BBC.

He said that he had detonated exploding targets before on his remote farmland west of Scottsbluff, Nebraska, without upsetting anyone.

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He said that Saturday's explosion contained blue smoke - caused by chalk powder - to tell the outside world that his wife Ashley is expecting a baby boy.

Image copyright Jon Sterkel Image caption Mr Sterkel and his wife Ashley are expecting a baby boy

Mr Sterkel, 26, can be heard proclaiming "it's a boy!" on the video of the explosion which has been widely featured on numerous US websites.

But the blast was so loud that police in nearby Scottsbluff were alerted, with some residents concerned that a major disaster had taken place.

Mr Sterkel said that he immediately called the local sheriff to explain what had happened in addition to apologising for his actions.

"I would like to say sorry for all of the confusion," he said. "I am a man of character and will willingly go to court if the district attorney chooses to prosecute me.

"This was just our way of announcing what gender our baby was."

Mr Sterkel faces charges for detonating the explosive without a valid permit. There was no damage or injury but he could be punished with a prison sentence and a fine of $1,000 (£800).

Police told the Omaha World Herald that although exploding targets, which are detonated when shot with a high powered rifle, have recently become popular, people who use them need to follow the correct procedures.

Mr Sterkel told the BBC that he does not plan any more spectacular blasts once the baby, his first child, is born around 16 June.

And the baby's name? "Possibly Wesson, in honour of the rifle maker Smith and Wesson," he said.