A group of three suicide bombers attempted to seize the main intelligence building in Afghanistan's southern city of Kandahar on Monday in a brazen daylight raid, officials said. The attack was the second big strike in weeks in the city, birthplace of the Taliban and the planned target of a mass offensive by NATO forces in coming months. "They were armed with guns, hand grenades and suicide vests," President Hamid Karzai's half-brother, Ahmad Wali Karzai, head of Kandahar's provincial council, told. "One of them managed to blow himself up and the other two were gunned down. Two security officials were wounded," he said, adding the situation was under control after an exchange of fire between the security forces and the assailants.The assailants threw a handgrenade at a school, wounding a teacher and another worker, he added.People fled the streets in panic and scores of police and army soldiers poured onto key city streets, witnesses said. The Taliban have staged a series of complex attacks, involving attackers and suicide bombers who attempt to seize government buildings, in several southern cities and the capital Kabul in recent months.In the biggest attack so far this year, fighters and suicide bombers struck several targets in Kandahar last month, killing more than 30 people.