既然你提到了flee与 flee from，这里也顺带说一下 escape 和 escape from。

▲通俗地说，escape 是处于某种情况之前的“逃避、躲开或避开”；escape from 是处于某种情况之后的“逃脱或解脱”。试比较：

The criminal suspect escaped the police. 犯罪嫌疑人躲过了警察的追捕。(未被抓住之前就躲避开了)

The criminal suspect escaped from thepolice. 犯罪嫌疑人从警察的手中逃脱了。(被抓住之后而逃脱了)

They escaped the fire. (逃过一劫，未身陷火海)

They escaped from the fire. (已身陷火海，但逃脱了)

▲flee说明逃走时的“急促、慌乱或仓惶”，着重强调动作本身而不强调结果。所以人们在实际运用中已将flee和flee from不加区分地通用了。如：

She fled (from) the room in tears. 她满脸泪水地逃出了房间。（《剑桥高级学习词典》）

They all fled (from) the burning ship.他们全从着火的船上逃出。（张道真《现代英语用法词典》）

He had fled from France at the time of the persecution. 他在大迫害时期逃离了法国。（《简明英汉词典》）

The purport of the message seemed to be that a few top army officers had fled from the country. 这个音讯的大意似乎是，有几名高级军官逃离了他们国家。（News from CNN2009-8-12）

During the civil war thousands of people fled the country. 在内战期间成千上万的人逃离了这个国家。（《牛津高阶英汉双解词典》）