(Cover) - EN Showbiz - Blake Lively and Ryan Reynolds have sparked rumours they are dating.

The Gossip Girl star announced today that her five-month romance with Leonardo DiCaprio had ended.

But E! Online are reporting that she may have already moved on to her Green Lantern co-star after they were seen together in Boston this past weekend.

They were apparently seen on an Amtrak train going from New York City to Boston where Ryan is currently filming R.I.P.D.

"Blake was late and almost missed the train," a passenger told the site. "The conductor didn't recognise here at first because she had a hat on."

The pair then sat together in the first class cabin.

To complicate matters, they had also been seen together the night before at the Roseland Ballroom in the Big Apple for the Radiohead show but Ryan's ex-wife Scarlett Johansson was also in attendance.

Blake and Ryan were witnessed having dinner together at sushi restaurant O Ya in Boston's Leather District, according to the Boston Herald.

The 24-year-old actress told earlier this year how she would try to lure Ryan into cheating on his diet.

"I would cook for the entire crew and I would try to lure him into eating some of the treats," she told Us Weekly about when they filmed the Green Lantern last year.

"Cupcake lollipops, fresh candies, homemade caramel and marshmallows covered in chocolate stuff like that. I was trying to sabotage him. I am a horrible person." (C) Cover Media