Check them over really really good under their feathers. Hawks like to bite and tear where big pieces of flesh are, like the back, breast, legs.
Wash off their injuries with an antiseptic. Spray their injuries with Vetricyn or an antiseptic spray if you have it. Respray every day for a while, and make sure their cuts stay clean.
They will be shocky and skittish for a while. They may not lay for a couple of days. Keep an eye out for other injuries that show themselves later on.
No antibiotics unless one of them has a gaping wound.
Is this your first hawk attack? If so, read up on hawks. Even though the one hawk might not be around, others will be back if your chickens are easy pickings. You got really lucky this time so I would consider it a warning. A small hawk can very easily kill a regular sized hen.
Hawks are also a protected federal species so be careful.