Thailand's police chief says at least 10 people were involved in the Bangkok bomb attack that killed 20 people.
He also said the attack had been planned at least one month in advance.
"It is a big network. There was preparation using many people," police chief Somyot Poompanmuang said. "This includes those who looked out on the streets, prepared the bomb, and those at the site and... those who knew the escape route," he said.
"There must have been at least 10 people involved."
Police had already said they were looking for three suspects, including a young man in a yellow T-shirt seen on CCTV apparently planting the bomb at the city's Erawan Shrine.
That man could be a foreigner, according to authorities, who released a sketch of the suspect.
Thailand's military leadership has declared the attack was unlikely to be the work of foreign militants and that it was not targeted at China, despite the shrine being popular with Chinese tourists.
Colonel Winthai Suvaree, spokesman for Thailand's National Council for Peace and Order, said: "Security agencies have cooperated with agencies from allied countries and have come to the preliminary conclusion that the incident is unlikely to be linked to international terrorism."
Victims' relatives have been struggling to come to terms with the tragedy, including a Malaysian family that lost four of its members.
Tan Kim Kee, 71, was devastated when she discovered her family had been caught in the blast.
"She cannot accept the truth," family friend Visen Lim Gin Seong said. "She has been crying nonstop since yesterday and asking why heaven is so cruel to the family when they have been so good to people."
Neoh Ee Ling, who is five months pregnant, was not injured in the attack but her 4-year-old daughter has been confirmed as one of the four family members dead and a fifth is also thought to have died.
"All the family members are distraught," said Lim. "It is also heartbreaking for friends and neighbors. They are good, friendly and generous people. Nobody expects this to happen.
"Seven of them went on holiday, but only two came back."
Nobody has claimed responsibility for the blast.
