KABUL — A pair of suicide bombers in Afghan military uniforms penetrated the most heavily guarded district of this capital early Wednesday, killing two Afghan security guards and wounding five civilians in blasts at a checkpoint near the main US military headquarters and half a dozen other international facilities.

Police officials said the bombers’ target was probably Camp Eggers, the large US military compound that occupies several square blocks of the Wazir Akbar Khan neighborhood. But a spokesman for the radical Islamist Taliban movement said the attack was aimed at a CIA compound and that ‘‘a large number’’ of insurgents had participated.