A man was left with a broken nose after being assaulted at a toilet block, police said.
Essex Police officers attended Eastern Esplanade, Southend-on-Sea, at about 19:30 GMT on Friday.
They found a man in his 30s had collapsed outside Namaste Village after being assaulted at a toilet block opposite the restaurant.
He was taken to hospital, having suffered a broken nose and cuts to the head, the force said.
Det Sgt Stacy King said restaurant staff provided emergency aid to the man and dialled 999.
She appealed for any witnesses to contact officers.