Two Taiwanese pilots were injured on Friday when their Apache attack helicopter crash landed on a building in northern Taiwan during a routine training mission, the military said.

The pilots were sent to a military hospital for treatment to slight injuries after crashing on top of the three-storey building in Taoyuan county but no civilians were hurt, a military official said.

Sean Lien, the son of Taiwan's former vice-president Lien Chan, Saturday won the ruling Kuomintang (KMT) party's nomination to run for mayor of Taipei.

The 44-year-old, who was born into one of the island's richest political families, has promised to donate his mayoral salary to charity if elected in November -- following a precedent set by former New York mayor Michael Bloomberg.

Taiwan President Ma Ying-jeou on Monday met Gina McCarthy, the first U.S. cabinet-level official to visit the island in 14 years, and hailed her trip as important for ties with Washington.

"This is the first time since 2000 for a cabinet-level official to visit Taiwan from the United States. It is of great significance for bilateral ties," Ma said while meeting McCarthy, administrator of the Environmental Protection Agency.

The top U.S. environmental official will visit Taiwan in the first trip by a cabinet-level leader from Washington to the Chinese-claimed island in 14 years, officials aid Saturday.

Gina McCarthy, the administrator of the Environmental Protection Agency, will travel to Taiwan and Vietnam from Monday through Wednesday to discuss cooperation, her agency said in a statement.

Hundreds of demonstrators surrounded a police station before staging a sit-in outside parliament late Friday to demand a top police official resign for removing protesters from parliament earlier in the day.

About 500 people surrounded a police station in downtown Taipei to voice their anger at its chief Fang Yang-ning, who had removed dozens of protesters who had refused to leave parliament after student activists ended their occupation of the main chamber.

Taiwanese protesters ended their occupation of parliament Thursday, three weeks after taking over the main chamber to protest a contentious trade pact with China.

"We came here with ideals, now we leave with more burden," student leader Lin Fei-fan said at a press briefing shortly before dozens of demonstrators clad in black t-shirts walked out of the building at around 1000 GMT.

Taiwanese protesters who have occupied parliament for three weeks to try to block a contentious services trade agreement with China said Monday they would end their protest this week after claiming success.

The demonstrators -- mostly young students -- occupied the main chamber on March 18 in the island's first-ever such protest.

Protesters said Monday they were considering ending their three-week occupation of Taiwan's parliament, after its Speaker intervened to try to end the standoff over a contentious services trade pact with China.

"Discussions about the direction of the movement are now under way," said Shih Yen-ting, a spokesman for the Sunflower movement which is staging the first parliamentary occupation in the island's history.

Taiwan riot police unleashed water cannon Monday to dislodge hundreds of demonstrators who had stormed government headquarters in violent scenes that dramatically escalated a days-old protest against a trade pact with China.

After nearly a week-long occupation of Taiwan's parliament, the protesters late Sunday also infiltrated the Executive Yuan where the cabinet offices are located, pulling down barbed-wire barricades outside and using ladders to break into offices on the second floor.

Student protesters occupying Taiwan's parliament to stop the government from ratifying a contentious trade pact with China on Friday vowed to take further action after the government failed to respond to their ultimatum.

The protesters say the deal will damage Taiwan's economy and leave it vulnerable to political pressure from China.