Three people have also been wounded in the shooting including a five-year-old girl, police say.
Three people were wounded, including a five-year-old girl, police said on Sunday.
A rifle and 9mm-calibre guns were found at the scene, the Ecuadorean Prosecutor’s Office posted on its Twitter account.
“We believe that this has to do with a struggle between organised criminal groups over the fight for territorial control,” National Police Commander William Villaroel told a news conference.
“At the moment, our investigation and intelligence units are carrying out operational actions in order to identify those responsible,” the National Police tweeted earlier on Sunday. There were no immediate arrests.
The gruesome attack, which one witness described as a shooting, occurred at a mechanic shop in the city’s southwest.
Bodies could be seen lying on the sidewalk in pools of blood, as people cried and hugged one another while police cordoned off the area, AFP reported.
Ecuador’s attorney general’s office said on Twitter that it had opened a “preliminary investigation into the murder of 10 people, following an armed attack on Saturday night”.
Local police also confirmed the death toll in Guayaquil, which has become one of the country’s increasingly bloody centres of a turf war between rival drug-trafficking gangs.
Recent surge of violence
The port city’s position on the Pacific coast makes it a strategic launch point for shipments of drugs to the United States and Europe.
The killing is the latest in a recent surge of violence, including gang- and cartel-related murders and multiple prison riots and massacres, as authorities crack down on gangs and seize drugs.
One witness to the latest attack, who asked not to be identified, told AFP that “there was a shooting” at a location where several people had been drinking when a group of assailants “on motorcycles came and ended the lives of those who were here”.
Since April 1, Guayaquil has been under a state of emergency, which allows the military to mobilise on the streets and implement curfews. The measure includes a curfew from 1am until 5am (06:00 until 10:00 GMT).
The South American country recently authorised civilians to carry and use guns for personal defence amid an increase in crime that the government has blamed on drug-trafficking gangs.