FOUR young men are wanted over the attempted sexual assault of a 38-year-old woman on Victoria's Mornington Peninsula.

The woman had been standing on the Hastings foreshore to watch the fireworks at the Western Port festival on Saturday night when the group of men attacked her, police said.

One man grabbed her from behind, a second stood in front of her and tried to pull her pants down, while two others stood behind the second attacker.

The woman fought off the men, who then ran away, police said.

All four are believed to be in their mid to late teens.

Detectives are investigating and have appealed for public help to nab the attackers.