* NSW premier vows to shut down Defqon.1 festival
* The dance, trance and techno festival an annual even since 2009
* Deaths reported in 2013 and 2015 on suspected drug overdose (Adds comments from New South Wales premier and organiser)
By Lidia Kelly
MELBOURNE, Sept 16 (Reuters) - Two people died, a dozen more were hospitalised and hundreds others sought medical assistance after suspected drug overdoses at a music festival in Sydney, the police said.
A 23-year-old man and a 21-year-old woman died on Saturday after collapsing at the Defqon.1 festival, the police said. Two of the 13 hospitalised people remain in critical condition, while about 700 sought assistance on site.
The police has charged 10 people with drug supply offences, including two teenagers who allegedly carried 120 capsules to the festival, held at the Sydney International Regatta Centre.
"I'm absolutely aghast at what has occurred, I don't want any family to go through the tragedy that some families are waking up to this morning, it's just horrible to think about," the premier of the Australian state of New South Wales, Gladys Berejiklian, said.
"This is an unsafe event and I'll be doing everything I can to make sure it never happens again," she added.
In 2013 and 2015, two men in their 20s died while attending the festival, both of suspected drug overdose.
The festival, an annual event held in Australia since 2009, has been organised by Q-Dance Australia, part of the Dutch event organiser Q-Dance.
On Sunday, the organisers said they were "deeply saddened" by the deaths.
"We are disappointed at the number of reported drug-related incidents, we have a zero-tolerance policy in relation to drug use at the festival," Defqon.1 said in a statement published by the Sydney Morning Herald.