"A terrible sound was heard there, despite all the security and safety measures. The matter is still under investigation," Reza Fallah, head of the Kerman Red Crescent Society, told state television. Later, the state news agency said the cemetery had been evacuated and closed until further notice. The government announced that Thursday would be a day of mourning. While the authorities did not publicly assign blame, top commander of Iran's Quds force Esmail Qaani said the attacks were carried out by "the agents of the Zionist regime (Israel) and the United States".