Low visibility and speeding were blamed for the accident which happened at the junction of two shipping lanes, the Ma Wan Fairway and Kap Shui Mun Fairway, about 8.10am.

"It might have been related to poor visibility, probably to speed and probably related to other vessels ... but the investigation will establish the cause,'' acting director of marine Roger Tupper said.

Visibility at Ma Wan dropped from 1.8 kilometers at 7am to only 370 meters an hour later.

The mainland-registered Nansha 38 was carrying 156 passengers and nine crew, while the mainland cargo vessel Zhong Hang 908 had a crew of seven.

The ferry returned to Tsim Sha Tsui and 102 passengers and crew were ferried to six hospitals. By 6pm all but seven - including two in serious condition - had been discharged.

``People sitting at the front rows suffered the worst hit because they were thrown from out of their seats,'' said a male passenger who escaped injury.

The cargo vessel continued to Yau Ma Tei to unload its cargo and await further investigation.

In a separate accident, a cruise ship, Wasa Queen, rescued two men after a collision with a small boat off Cape Collinson, Chai Wan, at 7am. One of the men was treated at a hospital and discharged.

dennis.ng@globalchina.com