A TEENAGER says she was knocked unconscious by a gatecrasher at her party.

Sian Gallagher, 17, hosted a gathering at her house in Christchurch, but the night took a nasty turn after two uninvited teenagers turned up.

She said one of the new arrivals then smashed a mirror in her room, and hit her after she forced him to leave.

Sian’s mum Sarah said: “A girl they know knocked on the door – she was with this boy, and they begged to come in, so she let them come in.

“He seemed to be quite drunk, and he knocked a drink out of Sian’s hand and then he went upstairs and smashed her mirror by kicking it, so they all decided he needed to leave.”

However, the boy, who is also accused of attacking two of Sian’s friends, began kicking the door after he was forced to leave.

Sarah said: “Sian ran out to stop him, and that’s when he took a swing at her.

“He connected and she fell and smacked her head on the pavement.”

Sian said: “I don’t remember anything.

“I can’t really remember anything that happened when I went down, but it took ages for me to realise what was going on because I’d been knocked out.”

The teen suffered with a serious headache and nausea for around a week after the incident at the end of February but did not have to go to hospital.

She said her alleged attacker had since been on Facebook to joke about the night’s events.

Sarah said: “He basically was laughing about it and said he didn’t remember anything, but later on he admitted remembering parts of the evening.”

A spokesperson from Dorset Police said an officer had suffered facial injuries and was taken to hospital on the night of the incident, but was later released.

She added that a 15-year-old Poole boy had been arrested on suspicion of assault.

A 17-year-old Bourne-mouth girl was also arrested on suspicion of assaulting a police officer. The boy was bailed until mid April and the girl until the end of April.

Any witnesses or anyone with information can call Dorset Police on 101.