Silent call.
I never speak when I pick up unknown numbers.
Other end hung up after a couple of seconds.

Pressed the 'talk' button & waited for the caller to speak. Silence for about 10 seconds, then caller hung up. Definitely a scammer-add it to your blacklist or block it.

I called back number (07) 3002 5698 rang once then gets disconnected automatically.

Scammer with middle eastern accent calling about 'my accident'. Hung up when I told him that I was reporting him.