High altitude lights

Hello, all.

A few weeks ago, in the middle of the afternoon (14:00ish, ISTR), I noticed
what (to me) appeared to be a couple of stars in the sky. They seemed to be
stationary. Visible below them were a couple of airliners, which leads
leads me to believe the "stars" were at a vary high altitude. I was unable
to observe them for lomg, mostly because of broken cloud, and the need to
be going elsewhere at the time!

The only conclusion I can reach is that they were man made satellites of
such a size or albedo that the light reflected made them visible in full
daylight. Any satellites I've seen previously have been at night, and to
the naked eye, relatively faint. I suppose the other option is that they
were aircraft at a very, very high altitude.

Can anyone shed any light on this, perhaps?

Thank you.

--
John Kirkland