Zac Efron Dating Lily Collins?

Are Zac Efron and British star Lily Collins dating?

Numerous sources have linked the two, who were spotted at STK restaurant in Los Angeles Saturday enjoying dinner together. Apparently, their romantically charged actions prompted passerby to believe that the stars have recently become involved.

"They even walked in holding hands," a witness told People magazine. Efron and Collins were attending a birthday party for one of Zac's friends.

Afterwards, the celebration continued outdoors.

"They had a drink at the bar together and then joined the birthday crew on the patio," said the unnamed spectator.

Efron, 24, and Collins, 22 didn't spend the entire night together, however. Although the "17 Again" star seemed to be having a good time with his date, he quickly left, exiting the restaurant without her.

Collins seemed unaffected, though, as she left more slowly.

"Zac literally ran to the car and jumped in, leaving Lily behind. But Lily kept her cool and took her time. She wasn't as worried about not being seen by us. … She probably didn't want to trip in her heels!" a source told X17online.com.

Later, Efron was seen partying at Lexington Social House with Miley Cyrus.

The appearance of the two publicly- although easily firing up speculations about their status- also helps to dispel other gossip about their love lives.

Collins, star of movie "Mirror Mirror," had been dating "Twilight" lead Taylor Lautner in 2010, but the two had reportedly split over unknown reasons. Now, it seems she's on the prowl for a new beau.

In addition, Efron had been linked to the recently-divorced Demi Moore, who allegedly "'tracked down' the High School Musical star at a party in L.A.'s Venice neighborhood," according to Us Weekly.

After the 24-year-old sent well wishes to Moore regarding the "personal stuff" she was dealing with, talk that Demi was looking for a romantic rendezvous with the youngster was largely disregarded.