CAIRO - Arab League ministers will pass a resolution blaming Syrian President Bashar Assad for last week's chemical weapons attack in Damascus when they meet in Cairo next week, League officials said on Wednesday.The states' permanent representatives at the League had already explicitly blamed Assad on Tuesday for the attack, which killed hundreds of civilians, in a step that provided regional political cover for a possible US-led military strike on Syria.A senior US official said planning was under way for possibly several days of attacks by several countries, likely to include its NATO allies France and Britain, to punish Assad.The higher-level endorsement by the Arab foreign ministers at their meeting on Sept. 2-3 is being pushed by Saudi Arabia and Qatar, which both back anti-Assad rebels in Syria's civil war, as well as Qatar, a non-Gulf official at the League said.