Orlando Halloween shooting leaves two dead and six injured

Two people have been killed and six injured after a gunman opened fire in Orlando while thousands of people were out celebrating Halloween.

A 17-year-old suspect has been arrested, according to police Chief Eric Smith, after gunshots were heard in two different locations and he was tackled by police.

'He pretty much walked into downtown, walked into the street and did what he did,' Chief Smith reportedly said, adding that the did not walk into any clubs. 

Horrifying video shows hundreds of people running for their lives after gunshots were heard in the downtown area of the city. 

The ages of the victims range from 19 to 39 years old, Smith said, and the dead and injured have not yet been identified as their families continue to be informed.

Young people - many wearing Halloween costumes - had been out partying last night in the area before the horror unfolded.

An emergency call came in just after 1am, with reports that several people had been shot around Central Boulevard and Orange Avenue, according to the Orlando Police Department.

A second call came in from out of Washington Street and Orange Avenue, Smith said.

Police had already been present at the scene and ran towards the gunfire, Smith said, allowing the suspect to be arrested quickly.

'Shortly after reported shots fired, a shooting suspect was located and taken into custody at Washington and Orange,' Smith said in his briefing this morning.

No firearms were used in the arrest, according to reports, with the only shots being fired by the gunman during the incident. 

Dozens of police cars and scores of cops were seen attending the scene in the early hours of this morning.

'The Orlando Police Department is conducting a shooting investigation in Downtown Orlando,' the force said in a statement. 

'We are still gathering information and interviewing witnesses. We will have more information later this morning.' 

Anywhere between 50,000 to 100,000 people are believed to have been downtown at the time of the shooting, judging by views of the huge Halloween crowds, Smith said. 

A separate shooting in Washington State last night saw one person killed at a shopping complex which was hosting a trick-or-treat Halloween event.