Hong Kong students strike on first day of school

It's been a busy day as thousands of protesters gathered in three locations across Hong Kong on Monday.

Take a look at how the day unfolded in the pictures below.

Large water-filled barriers have been installed in front of the entrance of Mong Kok police station, one of the scenes of protest over the weekend.

It's been a rainy, gloomy day in Hong Kong, but that hasn't deterred protesters.

If you're just joining us, here's what's going on today:

As if Hong Kong's summer of discontent wasn't chaotic enough, a leading pro-democratic lawmaker may have just been unseated by one of his own allies.

On Monday, a court ruled that 22-year-old Agnes Chow had been illegally barred from running for a seat on the city's legislative council last year.

Au Nok-hin, another pro-democracy candidate elected in her place, was "not duly elected," the judge said. 

It is unclear at this time what this means for the seat. Hong Kong's parliament now has 21 days to declare the seat vacant, if no appeals are lodged and the ruling holds. The decision could set the stage for a contentious new election, amid escalating protests.

Au and Chow are both prominent figures in this summer's pro-democracy movement, and were among several activists and lawmakers arrested last week.

Read more about Au and Chow here.

This is what the scene is like in Tamar Park, in front of the city's government buildings.

Protesters -- both young and middle-aged -- are sitting on the grass, some holding umbrellas and signs.

Many are waving signs that read: "Strike for Hong Kong. All citizens, go on three strikes." That's referring to the strikes happening today, which were intended to involve shops, schools and offices.

Some are wearing medical masks to protect their identities.

This is the scene at Chinese University of Hong Kong -- one of the city's top universities:

On the ground, protesters are waving placards. One features an anime interpretation of protesters in yellow hard hats and black face masks. The particularly muscular cartoon protester is carrying Pocari Sweat, a drink that has become a symbol of the pro-democracy movement.

There's also this sign, pinned to a stuffed doll of Pepe the Frog. While Pepe the Frog is a meme for the alt-right in the United States, he doesn't carry the same connotations in Hong Kong where he's become a regular feature in protest art.

Below, the stuffed frog's eye is covered and bloody -- a nod to a protester whose eye was injured during in an earlier demonstration.

It's been over 80 days since the first mass march on June 9, which organizers said drew more than 1 million people to the streets. Hong Kong Police put that number closer to 240,000.

There have been 1,117 people arrested since Hong Kong's summer of dissent kicked off on June 9 -- and almost 15% were arrested last weekend.

In a press conference Monday, police said they had arrested 159 people from Friday to Sunday. Assistant Commissioner of Police Mak Chin-ho said 132 were men and 27 were women. One was a 13-year-old boy arrested while carrying two Molotov cocktails.

During the weekend, protesters threw petrol bombs and lit bonfires on the streets, while police fired water cannons and tear gas.

The numbers make this past weekend one of the biggest for arrests in the three-month protest movement. During a city-wide strike last month, 148 people were arrested in a single day.

As thousands protest at the Chinese University of Hong Kong in the New Territories, high school students are gathering miles away in Hong Kong Island.

Many are in their school uniforms and wearing surgical masks -- something protesters frequently don to hide their identities.

Today is the first day of school for many Hong Kong students. But rather than going to class, some have opted to boycott and protest instead.