Five people were killed and about 40 injured after a lone driver ploughed a car into pedestrians on the bridge before stabbing a police officer outside British Parliament. 

READ MORE: CCTV shows woman plummeting into River Thames

Grace Reilly, 21, from Fairy Meadow was one day in to a long European holiday with her boyfriend and was sightseeing along the River Thames when the drama unfolded.

However, she said they weren’t frightened even though her environment was taken over by sirens and “chaos”.

“I was actually at the Tower of London walking down the Thames and didn’t even know anything was really happening,” Miss Reilly said.

“We just heard a bunch of sirens and saw a heap of helicopters. When I got some Wi-Fi at the restaurant we were at we found out about the attack going on.”

She said authorities and emergency services were frantic but the general demeanor of the public was of calm and people continued about their business. This included backpackers “continuing to drink in the bar”.

“We headed towards the [centre] of the city and there was so much chaos. I’d have to say every police car in the city must have been heading towards Westminster,” Miss Reilly said.

“The police were really, really on edge about everything. They kept asking if everyone was okay.

“A lot of the secret service were trying to get through the traffic pretty urgently. But a lot of people were calm where we were.”

The young traveler and her boyfriend will continue with their holiday and spend more time in the royal city undeterred.

“I know that the security will be very high around the city and be really watching out for anything suspicious and it actually makes it feel a bit safer,” she said.

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Expatriate Sonja Stojnic has lived in the UK for nearly a decade and heard about the attacks while she was at work. She said she felt safe heading home on the train.

She agreed that while there were more police on the streets, most people continued about their business and said locals are “not surprised”.

“We’re thankful there’s not more injuries,” Ms Stojnic said. “But we live in Europe, an attack is imminent.  Look what they have done in Germany, France and Belgium.”

FACEBOOK HELPS FIND LOVED ONES

Meantime social media giant Facebook is helping alert family and friends their loved ones are safe with a “safety check” feature.

People known to be in a terror affected area can click a button to send notifications to people letting them know they’re okay.