East Java Regional Police Spokesman Senior Commissioner, Frans Barung Mangera, told reporters here on Tuesday that police had made four arrests on Tuesday and nine arrests on Monday.
"The police arrested one in Pandaan, Pasuruan District; two in Malang; and another one in Surabaya," he added.
He noted that it was a temporary data and could increase any time. There are a number of cells that would be targeted based on the law.
"The figure excluded four suspected terrorists who were shot dead," the East Java Regional Police Spokesman revealed.
Mangera added that the bodies of the suicide bombers in Bhayangkara hospital were still unclaimed. "We hope that the relatives of the dead terrorists would come to claim the bodies. If no one comes, the police will bury them," he explained.
A total of 10 suicide bomb attackers died when they attacked three churches in Surabaya on Sunday and the Surabaya Police Headquarters on Monday.
The bombings also killed 12 people and wounded 43.