China's top negotiator on Taiwan was forced to cancel three public appearances during a landmark bridge-building visit after protests turned violent.

Zhang Zhijun, head of Beijing's Taiwan Affairs Office, was the first government minister to visit Taiwan since the island broke away from the mainland 65 years ago. Mr. Zhang's office said the four-day trip, which ended Saturday, had been intended to "listen to the voice of the Taiwanese people at the grass-roots level" as both sides sought reconciliation.

In a text message to reporters, Taiwan's Mainland Affairs Office, which is responsible for coordinating the trip with its Chinese counterpart, said the cancellation of Mr. Zhang's public engagements was made in response to a spate of "conflicts" in recent days.

On Friday evening, during his visit to the southern city of Kaohsiung, members of the pro-democracy Black Island Nation Youth Front threw white paint and bundles of paper ghost money at Mr. Zhang's vehicle as he was getting out of the car. Several security agents were splashed with paint.

Earlier that morning, also in Kaohsiung, a protester sustained a laceration to his forehead during a clash with China supporters in front of the hotel where Mr. Zhang was staying. The envoy was also almost hit by a water bottle thrown by a Taiwan independence activist as he arrived at the city's high speed railway station.