Two high-speed ferries collided in heavy fog Friday night between the neighboring Chinese territories of Hong Kong and Macau, seriously injuring 19 passengers, a Macau government spokesman said.

The fog was also blamed for other maritime accidents in the region.

The 19 hurt in the ferry collision — 10 men and nine women — suffered mainly head injuries and bone fractures that were not immediately life-threatening, said Alex Che, a spokesman for the government of Macau, which is a popular gambling enclave.

Wong Soi Man, director of Macau's Maritime Administration, said that the accident's cause had not yet been determined, but that "heavy fog must be one of the key factors."

Another 114 passenger suffered lighter injuries after the two vessels hit each other on their sides, Che said.

The accident occurred closer to Macau and the injured were being treated there, he said.

"All the glass shattered and the front of the ship fell off," a male passenger, identified only by the surname Chan, told Hong Kong's Cable TV.

Parts of China's southern coast were enveloped in fog due to a warm, humid maritime air stream.

The poor visibility was blamed for other accidents at sea.

Thick fog also hit China's commercial center, Shanghai, where an unlicensed river ferry carrying 22 people capsized Friday, leaving 10 people missing, China's official Xinhua News Agency reported.

The ferry, one of many that operate in the area without proper safety equipment or certification, sank near the city's Wusong pier shortly after the accident, Xinhua said.

In another incident, 66 people were rescued from a ferry that ran aground near the coastal city of Zhuhai near Macau, Xinhua said.

Hours earlier, another high-speed ferry traveling west from Hong Kong to Macau and carrying more than 370 passengers hit a small fishing vessel, said Hong Kong Marine Department spokeswoman Daisy Lo.

No one was injured and both vessels continued their journeys, Lo said.

Meanwhile, ferry operator Turbojet scaled back its services to Macau to once every half hour — from its usual peak frequency of every five minutes — and said travel time would take half an hour more than the usual one-hour journey.

The foggy weather slowed traffic on a key route that transports gamblers to booming casino enclave Macau, which surpassed the Las Vegas Strip in gaming revenue in 2006.