The assailants, travelling in as many as 10 SUVs, arrived at approximately 7.30 p.m. Sunday in the highland town of El Espinal, just north of the city of Mazatlan, said witnesses.
First, they shot and killed four people on one street. Thereafter they headed to a nearby home where they murdered two more people. The seventh victim was shot dead near a church, said officials Tuesday.
There have been no arrests so far, although army soldiers and state police were carrying out operations in the area to track down the assailants.
Sinaloa, the birthplace of the first generation of Mexican drug lords, remains the bastion of the Sinaloa cartel, regarded as the country's most powerful crime organisation.
The cartel's boss, Joaquin "El Chapo" (Shorty) Guzman, escaped from a maximum-security prison in Jan 2001 and his life on the lam has reportedly included visits to expensive restaurants and a lavish wedding attended by Sinaloa notables.
With a fortune estimated at $1 billion, "Shorty" Guzman appears on the latest Forbes magazine list of the world's richest individuals.
Conflict among rival drug cartels and between the criminals and the security forces has claimed 35,000 lives in Mexico over the last four years.
Deccan Herald is on WhatsApp Channels | Join now for Breaking News & Editor's Picks