Welsh runners who were taking part in the Boston Marathon have been talking about the bomb attack which claimed three lives and left more than 100 injured.
At least ten Welsh people were involved in the race with some of their families among the crowds.
They include one man from Cardiff who crossed the finishing line a minute before the first explosion.
You may find some of the images in Megan Boot's report distressing.
Matt Bauer was also part of a group from Cardiff running the Boston Marathon yesterday.
Pictured on the right here, with his friend Stuart Trimby, he told us he feels very lucky at having crossed the line just one minute before the explosions happened.
At least three people were killed in the blasts, and more than 100 injured.
Stuart Trimby from Cardiff told us how he was on the last mile of the Boston Marathon when he heard two explosions.
Pictured here with his friend Emma Clatworthy Davies before the race, he said he feels "shock and sadness" at the way a positive occasion was ruined by the explosions.
You may find some of the images in the video upsetting.
Neil Lewis from Cardiff was among the Welsh people who ran the Boston Marathon.
His wife and 20-week-old baby daughter were at the finishing line just an hour before the explosions, and he told us about his relief they didn't go back out to watch other people finish.
He was speaking to us by phone from Boston, describing the city as "eerily quiet", the morning after the explosions.
At least three people died in two blasts near the marathon finishing line.
You may find some of the images in this video upsetting.
The organisers of the London Marathon say they "fully expect" it to go ahead as planned on Sunday, although "security will be reviewed", after two explosions hit the Boston Marathon yesterday, although "security will be reviewed."
Vale of Glamorgan MP Alun Cairns is among the Welsh runners taking part, and has urged others to "turn out in confidence."
The head of crisis management department at the Foreign and Commonwealth Office has said a hotline number will remain open 24/7 to callers in the UK who are seeking information on loved ones in relation to the Boston bombings.
The main FCO number is 020 7008 1500.
The UK Consulate in Boston has tweeted contact information for anyone needing help after the marathon explosions: