An outing to watch a fireworks display to mark China's National Day which coincides with the mid-autumn festival this year ended up in tragedy for many in the passenger boat that belonged to the Hong Kong Electric Company.

At least 36 people have died and many more injured as the vessel collided with another boat, owned by Hong Kong and Kowloon Ferry Holdings, off Lamma Island, south of Hong Kong.

At least 28 people were declared dead at the scene of the tragedy while eight others were pronounced dead later at the hospital.

Though the details of the victims are yet to be released, UK tourists are thought to be involved in the tragedy as the island is a popular destination for tourists and expatriates.

Nearly 123 people have been rescued so far including several children, according to the Fire Service Department officials.

The reason for the collision is unclear and is being investigated. "We must understand the reason for this incident," said Hong Kong Chief Executive CY Leung.

"Our captain is not well and we have not been able to talk to him so far," said a spokeswoman for Hong Kong and Kowloon Ferry Holdings.

"Over 100 people were sent to five hospitals during the incident, nine of them have sustained serious injuries or are in critical condition," said the Hong Kong government.

"Within 10 minutes, the ship had sunk. We had to wait at least 20 minutes before we were rescued," one of the survivors told Reuters.

The other boat with a damaged bow, docked at Lamma Island. It reportedly had over 100 passengers and many of them suffered injuries and were taken to the hospital.

Rescue operations involving diving teams, search helicopters and boats are still going on since the authorities are not ruling out the possibility of people still trapped inside the vessel.

Lamma Island lies three kilometers (two miles) south-west of Hong Kong and is one of the three islands of Hong Kong.

Scroll through the pictures to witness the tragedy that struck the boat revellers:

Rescuers approach a partially-submerged boat after two vessels collided in Hong Kong.Reuters
Rescuers approach a partially-submerged boat after two vessels collided in Hong Kong.Reuters
Rescuers approach a partially-submerged boat after two vessels collided in Hong Kong.Reuters
A rescuer checks a partially submerged boat after collision in Hong Kong.Reuters
A sunken ferry is lifted out of the water after an accident off Hong KongReuters
A police boat sails near a sunken ferry being lifted out of the water after an accident off Hong KongReuters
A survivor is taken onto shore by rescuers after a collision involving two vessels in Hong Kong.Reuters
Two survivors, accompanied by rescuers, are taken onto shore after a collision involving two vessels in Hong Kong.Reuters
Firemen move a body in the water after two vessels collided in Hong Kong.Reuters
A relative cries as she leaves a public mortuary keeping bodies of those who died in a boat accident in Hong Kong.Reuters
Police officials carry a body recovered from the sea after an accident in Hong Kong.Reuters
Relatives of victims in a fatal ferry collision pay their respects by throwing paper money into the waters off Hong KongReuters
Fireworks are seen over Victoria Harbour as Hong Kong celebrates the 63rd anniversary of the founding of the People's Republic of China.Reuters