I just came out of the famous hanuman setu temple back gate of the city on the choti diwali festival yesterday and as i was waiting for my cab , my eyes turned left towards the metro line above and just above it a strange object rushed extremely fast through the sky with a greyish and whitish trail as well as a same coloured cloud around it. i with my mom and brother immediately pointed them to look over it but it vanished within 4 secs till i made them look at it. the object vanished and i initially thought of a firecracker rocket but it wasn't as it was ascending upwards with no colour except a grey and white cloud and trail. it was my first experience of an ufo ,the cloud formed was lit by it but got vanished as the object disappeared.