Image caption The pleasure boat Lamma IV collided with a ferry and then began to sink, throwing many of those on board into the water

Seven crew members have now been arrested from the two boats that collided in the waters off Hong Kong, leaving 38 people dead.

Those held on suspicion they did not "exercise the care required of them by law" include the captains of the two vessels - a public ferry and a company boat.

Five children are among the dead after the boats collided on Monday evening.

One of the boats half-sank following the accident off Lamma Island.

The accident - the worst maritime accident in Hong Kong for over 40 years - has caused shock in Hong Kong, where thousands of people travel by boat among the territory's islands every day, say correspondents.

Some relatives of those feared lost have gathered at mortuaries to seek news of their loved ones, reported Associated Press news agency.

Analysis Unlike mainland China, transport accidents resulting in fatalities are extremely rare in Hong Kong. This city of more than seven million people prides itself on highly regulated, efficient forms of mass transport by road, underground and by sea. Hong Kong was founded as a deep-water port more than 150 years ago. Its surrounding waters are home to some of the busiest shipping routes in the world. Its location close to the Pearl River Delta means vessels carrying cargo ply those waters everyday. In addition to the commercial ships, leisure and fishing boats are common sights, but serious collisions are uncommon. Thousands of people take regularly scheduled ferries from Hong Kong's main islands to outlying territories such as Lamma Island, which is a very popular area for both tourists and residents.

Busy waters

Dozens of people were thrown into the waters after the pleasure boat Lamma IV, carrying employees of Hong Kong Electric and their family members to watch a firework display, was in collision with the ferry.

It partially sank within minutes of impact, while the ferry - operated by the Hong Kong and Kowloon Ferry (HKKF) company - was able to reach Lamma and disembark its passengers although it was taking on water.

Twenty-eight bodies were recovered overnight, eight more people were declared dead at hospitals, and two more bodies were discovered on Tuesday, the government said.

More than 100 people were injured. The number of people missing is unknown.

At an earlier briefing the head of police, Tsang Wai-hung, said the arrested suspects "responsible for manning the two vessels had not exercised the care required of them by law to ensure the safety of the vessels as well as the people on board".

The crash is Hong Kong's worst maritime accident since 1971, when a ferry sank during a typhoon, leaving 88 people dead.

It occurred during a busy period for passenger travel, at the end of a long holiday weekend to mark the mid-autumn festival that this year coincided with China's National Day on 1 October.

On Tuesday, some relatives of the dead went to the scene to throw paper money into the waters in tribute to those lost, AP said.

'Isolated' accident

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Hong Kong Electric is owned by Li Ka-shing, Asia's richest man. On Tuesday his son, Victor Li, said the company would make a payment of HK$200,000 (£16,000; $25,800) to the family of each person killed.

His father told reporters on his way to visit a hospital on Tuesday that he was "very sorry", but did not want to say too much, reported AP.

Hong Kong Chief Executive CY Leung dismissed concerns that the accident would damage Hong Kong's reputation as a centre of global maritime trade.

"This is definitely an isolated incident. The marine territory of Hong Kong is safe," he said.

He said an independent committee would be set up to look into the causes of the crash, and suggest measures to prevent similar tragedies in future.

He declared three days of mourning starting on Thursday, and expressed his sympathy with the victims' families.

1. Hong Kong Electric boat departs power plant for firework display in Victoria Harbour

2. Ferry departs Hong Kong island on regular route to Lamma Island

3. Collision occurs north of Lamma Island. Damaged ferry continues to port at Yung Shue Wan. Lamma IV sinks.

Lamma lies some 3km (two miles) south-west of Hong Kong island, and is popular with tourists and expatriates.

Hong Kong is one of the world's busiest shipping channels, but its ferries have a good safety record.