Two of them spoke to us and gave their accounts from the scene of the explosion.

Sathish Krishnan

BBC News Online user Sathish Krishnan took this picture of the blast site

I was just getting out of my apartment building, which is a few hundred metres away from the site of the blast when I heard a thunderous explosion.

The sound was deafening and it had a sudden impact on everyone around.

Immediately there was chaos, as people started running for cover.

The immediate thought that came to my mind was something must have blown up in my apartment complex, so close was the impact felt even though the blast site, the Australian Embassy, is about half a kilometre away.

When I looked around, I could see thick white smoke looming large like a column in the sky from the street where the embassy is situated.

Colleagues of mine were crossing the road near the embassy when the blast happened and they saw limbs and blood everywhere

I was on the scene around 15 minutes after the explosion. There were people everywhere on the road.

People were stunned, curious, panic-stricken and also, very surprisingly, a few were screaming in excitement, going towards the blast site in their two-wheelers.

As I got closer to the blast site, the overall impression was one of confusion.

Nobody was clear about where the blast actually occurred.

People were moving here and there when the police and ambulances arrived.

Almost every building in the vicinity has suffered huge damage. The window panes were shattered and the solid concrete buildings looked as if they had been ripped apart by a giant pair of scissors.

Everyone was trying to get closer to the site to know what had happened.

Colleagues of mine were crossing the road near the embassy when the blast happened and they saw limbs and blood everywhere.

John Day

I work just 100 metres (330 ft) from the embassy.

I was in a meeting and felt the whole building shake in a huge explosion.

A mushroom of dirty white smoke whooshed up above the embassy.

Bits of our building's cladding crashed down and the windows of the large office buildings across the road shattered.

Shrapnel flew across the area making gaping holes high up in the tall buildings.

People rushed out of the offices and ran down the road to where the bomb went off.

One girl in our workplace went all the way to the bomb crater and came back traumatised crying in the office.

We checked that all were OK in the office and watched the fleets of ambulances, fire engines and police vehicles rushing to the scene.

You could not get a telephone line to find out what was going on. There were traffic jams everywhere.