Two US soldiers were killed and two wounded when a gunman wearing an Afghan military uniform opened fire on their vehicles as they left a Kabul prison, officials said Monday, while one civilian was killed and five wounded in a separate rocket attack in the Afghan capital, DPA reported. Afghan soldiers providing security at the Pol-E-Charki prison on the eastern outskirts of the capital rushed to the aid of the US personnel and fatally shot the "rogue soldier," who was wearing an Afghan National Army uniform, the US military said in a statement Monday. The statement did not identify the victims in Sunday's incident but said the two wounded soldiers were in stable condition. US and Afghan officials were investigating the incident, it said. However Defence Ministry spokesman General Zahir Azimi, while confirming that the attacker was an Afghan army soldier, said that he was suffering from a mental illness. In a separate incident, a rocket slammed into a house in eastern Kabul Monday morning, killing one person and wounding five, including two children, said Alishah Paktiawal, investigation chief for Kabul. "A rocket fired from an unknown location hit a residential house in the Banayee area of Kabul city," Paktiawal said. It is the first time that Kabul has suffered this type of attack this year, raising fears that despite its heavy security, insurgents are closing in on the capital.