SPRINGFIELD, MASS. >> Springfield police have arrested three people and seized nearly 17,000 bags of heroin.

The arrests Thursday morning were made after a lengthy investigation into what police call major distributors of heroin throughout western Massachusetts.

The suspects, Jeremy Crespo, of Holyoke, and Moises Silva and Jereiska Fontanez, both of Springfield, are being held without bail and face arraignment Friday on drug and gun charges.

The two men were tailed by police through several cities where they allegedly made drops to street-level dealers. They were arrested in a gas station parking lot.

Investigators then executed a search warrant on an apartment where arrested the woman and found the heroin, as well as cocaine and marijuana, more than $11,000 in cash, a loaded gun and drug weighing and packaging paraphernalia.