A widower has told how he tried in vain to save his drowning wife in a tragedy which also claimed the lives of his nine-year-old son and a family friend.

Waris Ali, from Glasgow, said he had taken off his shirt and tried to throw it into Loch Lomond so that his wife, Edina Olahova, could grab on to it but that she was unable to do so.

Ms Olahova, 29, and son Rana Haris Ali, died in the incident along with Muhammad Asim Riaz, 41, the family friend, on Saturday evening.

The incident unfolded after Mr Riaz’s seven-year-old son fell into the water after playing at the end of a pier. The adults and the other child went into the water, which Mr Ali said appeared shallow and safe, in a bid to rescue him but soon got into difficulties.

The seven-year-old was saved with the help of a Scottish man, he said, with Mr Riaz the only member of the group who could swim. The seven-year-old remains in hospital in Glasgow.

Mr Ali told the BBC: "When I came out from the water, I could see my wife’s hand. I tried to pull off my shirt and give it to her to catch but she couldn’t."

The incident was one of four tragedies in open water in Scotland at the weekend in which six people, including four boys, died.

Loch Lomond is one of Scotland's most popular national parks

Credit: ALAMY

The group was returning from a holiday in Loch Lomond when they decided to stop at the popular beauty spot.

The incidents have sparked a series of warnings from emergency services about the dangers of swimming in open water.

Deputy Assistant Chief Officer Alasdair Perry, from the Scottish Fire and Rescue Service, said: "This is the worst weekend in relation to incidents of this nature that I can remember."

First Minister Nicola Sturgeon described the deaths as "heart-breaking human tragedies".

She said: "Like everyone else around the country, my thoughts are with the families who are grieving loved ones right now.

"It is unimaginable and impossible for the rest of us to understand fully what they are going through.

"These tragedies over the weekend are a really brutal reminder that the beauty of some of our waters often belies the dangers that they hold."