Tributes across Australia for Bali Nine

Some were fuelled by anger and others by grief, but the tributes for executed Australians Andrew Chan and Myuran Sukumaran have poured in.

Grief is flowing and anger towards Indonesia is building after it executed two Australian prisoners. (AAP)

"I pity your heart Joko".

It was a simple yet powerful message tied to the front gate of the Indonesian consulate in Sydney in the hours after the execution of Andrew Chan and Myuran Sukumaran.

The curt, handwritten note to Indonesia's president Joko Widodo accompanied bunches of flowers from those touched by the drug smugglers' deaths.

A collective outrage came as the family of the executed men voiced their anguish.

"I have just lost a courageous brother to a flawed Indonesian legal system. I miss you already RIP my Little Brother," Andrew's brother Michael Chan tweeted.

The Catholic Archbishop of Sydney said that "in some ways capital punishment punishes the families more than those executed".

"They must carry the memories for years to come," Archbishop Anthony Fisher said.

Floral tributes were left at a makeshift memorial in Sydney's Martin Place, where hundreds held an 11th-hour candlelight mercy vigil on Tuesday night.

"They weren't asking to be pardoned from punishment, they were just asking for their basic human need to live," one woman who laid a tribute told AAP.

Outside the Sydney home of Chan's parents, a neighbour laid flowers alongside two burning candles.

"I think the anger's going to come for a lot of us, it's not here yet. It's just sadness," the neighbour said.

Online, more than 54,000 people tweeted using the hashtag #istandformercy in the past 24 hours.

On Twitter, more then 5000 people urged Australians to boycott Indonesia and its island province Bali - something that Prime Minister Tony Abbott has cautioned against.

Qantas chief Alan Joyce said there was no sign of travellers avoiding Indonesia.

"Our expectation is there probably won't be a significant impact on those operations," he said.

A small group of protesters gathered outside the Indonesian consulate in Darwin, calling on Australia's northern neighbour to "stop murdering people".

There were similar protests planned around the country and overseas.

In Canberra, a group of about 35 braved the night chill outside the Indonesian Embassy, but by morning, any signs of their vigil had been cleared.

A lone protester, Lynn Russell, held up a "Widodo a coward" sign.

But not everyone was so kind to Chan and Sukumaran.

"I'm having a hard time finding even an ounce of sympathy for the #BaliNine. You reap what you sow, folks" wrote an Australian on Twitter.