By George P. Hassett

Two Boston men were arrested on drug trafficking charges last week in Assembly Square after an undercover Somerville police officer infiltrated their gang, police said.

Police say Waner Baez, 29, and Alexis Crespo-Gonzalez 31, worked within a heroin distribution organization that sold drugs in Somerville and surrounding cities. They were arrested Thursday, April 15 at the 99 Restaurant after they allegedly sold 70 grams of heroin to the undercover officer.

After receiving the heroin the officer signaled an arrest team. Police allegedly found cocaine on Baez when they handcuffed him.

Baez was arrested and charged with trafficking in heroin, distribution of a class A drug, conspiracy to violate a drug law and possession of a class B drug.

Crespo-Gonzalez was arrested and charged with distribution of a class A drug, conspiracy to violate a drug law and trafficking in heroin.