Twin car bombs killed 21 people in Karbala in southern Iraq on Monday, while four people died in a suicide attack on a television channel in Baghdad. The suicide blasts in Karbala, where religious commemoration ceremonies are due to begin Wednesday, occurred at around 7:00 pm (1600 GMT) and also wounded at least 47 people, a provincial health official said. Eyewitnesses said one vehicle exploded at a security checkpoint on the southern outskirts of the city and the second blew up a short time later just yards away. “Most of the killed and wounded are policemen and civilians,” said Salim Kadhim, spokesman for Karbala's health directorate, adding that 21 people had died and 47 were wounded. Meanwhile, a suspected Al-Qaeda suicide bomber blew up a car outside the Baghdad offices of Al-Arabiya television in the city center, killing four people a month after the Dubai-based channel was warned of insurgent threats. The bomber struck at around 9:30 am (0630 GMT), leaving a massive crater and sending a plume of smoke into the air that could be seen from several kilometers away. Majid Hamid, a journalist for the pan-Arab satellite channel, said four people were killed -- three security guards and a female office assistant. That toll was confirmed by an official at Al-Yarmuk hospital in west Baghdad. An interior ministry official, speaking on condition of anonymity, put the casualty toll at three dead and 16 wounded. Former deputy prime minister Salam Al-Zawbayi was among the wounded. “There was a huge explosion that shook the building -- all the rooms were damaged,” Al-Arabiya journalist Tareq Maher told the channel in a live broadcast. The street in front of the channel's offices was covered in shards of glass and debris, with nearby buildings and several cars showing signs of damage. Baghdad security spokesman Major General Qassim Atta blamed Al-Qaeda for the attack. “These are the methods of Al-Qaeda,” he said. “The goal of this operation was to attract media attention.” Atta said the explosives-laden vehicle had passed through a checkpoint, and charged that there may have been “cooperation” between the driver and the guards. Major General Jihad Al-Jaabari, the head of the Iraqi army's explosives handling unit, said the bomber was an Iraqi and added that the vehicle was carrying more than 100 kilograms (220 pounds) of ammonium nitrate.