Al-Maliki said the attackers' apparent use of two mentally disabled women to carry out the bombings showed their "moral degradation" and how much they "hate mankind."
In a statement, the prime minister also swore on the blood of the victims that the government will achieve its goals in securing a stable Iraq. Al-Maliki said the terrorists will be crushed and their strongholds targeted.
Officials said the blasts at two markets in Baghdad left 99 people dead and up to 200 wounded.
The death toll was the worst in Baghdad since April 18, when multiple car bombings killed 191 people around the city.
The first device was detonated at the busy Al-Ghazil animal market, which had been a previous target for attacks, while another bomb tore through a crowded market in the Jadida area of east Baghdad.
Earlier today, Iraq's chief military spokesman in Baghdad, General Qassim Ata al-Musawi, said the attacks were carried out by women who both had Down's syndrome and may not have understood they were being used for suicide missions.
Al-Musawi said the explosives they carried were detonated by remote control.
Al-Qaeda in Iraq, blamed by the U.S. military for most other large-scale bombings, has increasingly used women wearing suicide vests to carry out strikes.
Attacks have fallen dramatically across Iraq since June 2007, when 30,000 extra U.S. troops were deployed.
Some 20,000 combat soldiers are to be withdrawn from Iraq by the middle of this year, leaving around 135,000 U.S. soldiers in the country.