Police fired water cannons early on Monday to disperse thousands of anti-nuclear protesters blocking a main traffic route in Taiwan's capital, Taipei.

The demonstrators, most of whom were lying on the ground, had blockaded one of the city's busiest streets over the weekend.

Anti-nuclear power activist groups had called on thousands to mark the 28th anniversary of Chernobyl nuclear disaster on Saturday by staging sit-in demonstrations along a main street near Taipei's central train station.

After the city's mayor, Hau Lung-pin, ordered police to disperse protesters 'by all means', more than 3,000 officers and two water cannons were mobilized.

Having failed to expel the demonstrators by 3 a.m. early on Monday, police turned to the water cannons.

Some protesters were rounded up by police and transported outside the protest site.

The at times violent clash reached its lowest point at roughly 4 a.m. when riot police broke through protesters' defense line. The demonstrators responded by building new fortifications using large plant pots and dumpsters taken from the surrounding area.

The water cannon assault continued until 5 a.m., by which point the vast majority of protesters had been expelled.

Riot police soon made their way to a nearby underground passageway, where protesters made makeshift fences from safety cones and doused cooking oil on the ground to keep the officers at bay. The police countered by spraying dry chemical extinguisher and continued firing the water cannon.

By 7 a.m. the entire group of protesters had been expelled and traffic had returned to normal. A total of 54 protesters and 30 police officers sustained injuries, and six people were arrested.

In a press conference Taipei mayor Hau made no excuses for the police's actions and said that authorities merely acted to maintain order in the city.

The protests forced Taiwan's government to halt construction on its nearly completed fourth nuclear power plant and President Ma Ying-jeo