At first glance they look like Bluebells to me.

Are bluebells not same as african lilies?

No African lilies are an Agapanthus, bluebells are Hyacinthoides non-scripta. Looking at the photo I suspect they are the Spanish bluebell (Hyacinthoides hispanica) which is slowly but surely wiping out the native bluebell.

They definitely are bluebells, and I have never heard of bluebells also being known as African Lilies.

on the far right there appears to be a muscari too.

And Agapanthus (African Lilies) flower mid-late summer with flowers in a dense umbel , not arranged up a scape (flower stalk) like these.

OK, so they are bluebells. any taker for my second part of the quesion? :-)

You can collect the seeds once they are ripe and sow but frankly you will find it easier to let them self seed. If you do collect the ripe seed fill a small plant pot with potting compost almost to the top, sprinkle the seed on and cover with a thin layer of compost or grit. Label and place the pot in semi shady conditions, preferably where you want the bulbs to be when they grow. In around 2 years you will se what looks like grass growing out of the pot, it will take another few years for the bulbs to grow to flowering size. We grow lots of bulbs from seed and it is not a quick process.

yes take the seed heads off and remove the dead leaves and the bulbs will come up again next year.