A pair of swans targeted with crossbows have been rescued from the River Lagan by animal welfare experts.

The mute swans were rounded up using nets and taken to an animal hospital for treatment, the USPCA said.

The female of the pair was left with a crossbow bolt piercing her neck while the male had been stabbed in the back with another bolt.

Officers from Northern Ireland Fire and Rescue Service helped to bring the animals to safety, USPCA spokesman David Wilson said. He has called for tighter rules on the sale of crossbows and a strict ban on selling them to children.

It’s believed the birds were attacked last week and a two-hour attempt to capture them on Monday proved in vain as they took to the air when anyone came close. But yesterday's effort at Lambeg on the River Lagan, where the swans have lived for a couple of years, met with success.

“The Fire and Rescue Service were key to the rescue. We got nets across the river at a narrow point where the swans couldn’t take off,” Mr Wilson said.

“Then we shepherded them up into the nets and managed to get them out of the water. It went amazingly well — it could have turned into a disaster.”

Mr Wilson said it is still too early to predict how well the swans will recover from their ordeal.

“One is sitting up preening itself, but they both have crossbow bolts in them. We will know more soon,” he said.

It is believed the pair were attacked on Wednesday or Thursday. Walkers who spotted the female with the bolt stuck in her neck reported the incident to police who then called in the USPCA.

“The availability of crossbows is a disgrace, considering the ease with which they can be bought and misused on wildlife and people’s pets,” Mr Wilson added.

“I would like to see some kind of registration system where there is a register kept of ownership. There should be an age limit on their purchase — at the moment a 10 or 11-year-old can walk into an unscrupulous sporting shop and buy one and we think that is a disgrace. It’s the swans that pay the price.

“Crossbows are a very powerful weapon over a short range with a velocity similar to a bullet.

“I’d like to see the people who did this in front of a court. They are creating mayhem and great distress to the birds they are attacking. These animals can’t defend themselves.”