Yes. That's a key part of what an estate agent usually does. If there's serious interest, people can still be slow to make the first offer. I'd say to call all the viewers who looked interested, tell them there's an offer and the level, and ask if they have any further interest in the property. Not in a pressurised way, but if they need time to think about it, do give them a deadline to get back to you so you can be fair to the current bidder. Your aim is to get the best offer you can - that may very well be that first bid, so you don't want to lose that one by stringing someone along.
Good luck
d