Beer saved runner's life: Warning: Graphic image.

Rotorua's Paul Charteris says his friend escaped the Boston Marathon bombings after going in search of a celebratory drink following the race.

Two bombs exploded at the end of the Boston Marathon yesterday with three people confirmed dead and 105 injured.

Mr Charteris said his friend posted on his Facebook page with a title which read "my life was saved by a beer".

Mr Charteris said his friend had lined up by the finish line in search of a cold beer but lost patience and moved on.

"He was frustrated that it was so busy at the finish line [and] he could not be bothered queuing up for a beer," Mr Charteris wrote on the Rotorua Daily Post Facebook page yesterday.

"He walked down the road to a pub and heard the explosions from there."

Athletics New Zealand said 45 Kiwis were registered as running the marathon, but none were from the Rotorua area.

The Ministry of Foreign Affairs and Trade reported yesterday afternoon they had not received any reports of New Zealand runners or spectators being injured.

It is still unclear exactly who planted the bombs and why.

Rotorua runner Sarah Biss said she had thought about going to the Boston Marathon this year but had decided against it because of injury.

Ms Biss said, that luckily, her friends from Kenya and the United States had finished the race well before the bombs went off, and had left the area.

It was reported yesterday a Tokoroa man, Adam Tafau, was only 100m from the explosions.

Mr Tafau reportedly said he was getting ready to board a train when the explosions went off.

"I heard what sounded like big claps of thunder, which I though was bizarre because it was a fine day," he told the Waikato Times.

"Police and ambulances zoomed past. I thought nothing of it till I boarded the train, at that point we had no idea what had happened, the train stopped and the conductor said the train would not go any further and that we had to get off immediately."