A secretive Syrian military unit at the center of the Assad regime's chemical weapons program has been moving stocks of poison gases and munitions to as many as 50 sites to make them harder for the U.S. to track, according to American and Middle Eastern officials.

美国和中东官员表示，处于阿萨德政权化学武器计划核心的叙利亚某秘密军事组织一直在将大量毒气和弹药转移至多达50个地点，目的是让美国更难以追踪到这些武器的下落。

The movements of chemical weapons by Syria's elite Unit 450 could complicate any U.S. bombing campaign in Syria over its alleged chemical attacks, officials said. It also raises questions about implementation of a Russian proposal that calls for the regime to surrender control of its stockpile, they said.

官员们说，叙利亚精锐部队Unit 450转移化学武器的做法可能会使美国的轰炸行动复杂化。据称，叙利亚政府曾发动化武攻击，美国因此要对叙利亚动武。这些官员说，这还会让外界质疑如何执行俄罗斯呼吁的阿萨德政权放弃武器控制的计划。

U.S. and Israeli intelligence agencies still believe they know where most of the Syrian regime's chemical weapons are located, but with less confidence than six months ago, U.S. officials said.

美国官员说，美国和以色列情报机构仍认为，他们知道叙利亚政权大多数化学武器存放在哪里，但自信程度如今不如六个月前。

Secretary of State John Kerry met Thursday in Geneva with his Russian counterpart to discuss a road map for ending the weapons program. The challenges are immense, Mr. Kerry said.

美国国务卿克里(John Kerry)周四在日内瓦与俄罗斯外长会面，讨论终止阿萨德武器计划的路线图。克里说，挑战非常艰巨。

The U.S. alleges a chemical-weapons attack by the Syrian government on Aug. 21 killed more than 1,400 people, including at least 400 children. Syrian President Bashar al-Assad on Thursday again denied any involvement in a chemical attack, but he said his government was prepared to sign an agreement banning the use of chemical weapons. Syrian officials couldn't immediately be reached for comment on the weapons.

美国称，叙利亚政府今年8月21日发动了化武袭击，造成1,400余人死亡，其中至少包括400名儿童。叙利亚总统阿萨德(Bashar al-Assad)周四再次否认参与过任何化武袭击，但他说叙利亚政府准备签署一份禁用化武协议。无法立即联系到叙利亚官员就化学武器相关事宜置评。

Unit 450 -- a branch of the Syrian Scientific Studies and Research Center that manages the regime's overall chemicals weapons program -- has been moving the stocks around for months, officials and lawmakers briefed on the intelligence said.

知晓相关情报的官员和国会议员说，叙利亚科研中心(Syrian Scientific Studies and Research Center)下属机构Unit 450连月来一直在转移武器。该中心管理着阿萨德政权的全盘化学武器计划。

Movements occurred as recently as last week, the officials said, after Mr. Obama said he was preparing to launch strikes.

这些官员说，近在上周还有转移武器的活动发生。此前，奥巴马说准备发动袭击。

The unit is in charge of mixing and deploying chemical munitions, and it provides security at chemical sites, according to U.S. and European intelligence agencies. It is composed of officers from Mr. Assad's Alawite sect. One diplomat briefed on the unit said it was Alawite from 'janitor to commander.'

欧美情报机构称，Unit 450不仅负责化学弹药的混合和部署，还负责化武存放地点的安全。该机构人员由阿萨德麾下阿拉维派官员组成。一位知情外交人员说，这个机构从看门人到指挥官都是阿拉维派。

U.S. military officials have looked into the possibility of gaining influence over members of Unit 450 through inducements or threats. 'In a perfect world, you would actually like to co-opt that unit. Who cares who pays them as long as they sit on the chemical weapons,' said a senior U.S. military official.

美国军方官员在研究是否可通过引诱或威胁对Unit 450成员施加影响。美国一位高级官员说，理想情况下，实际上你会希望团结该机构成员，只要他们拥有化学武器，管他们的老板是谁。

Although the option remains on the table, government experts say the unit is so close knit that they doubt any member could break ranks without being exposed and killed.

虽然这一方案并未被排除，但政府专家说，Unit 450的成员关系非常紧密，很难相信会有任何成员背叛该组织而不被暴露和杀害。

The regime traditionally kept most of its chemical and biological weapons at a few large sites in western Syria, U.S. officials said. But beginning about a year ago, the Syrians started dispersing the arsenal to nearly two dozen major sites.

美国官员说，叙利亚政权的传统做法是将大多数化学和生物武器存放在该国西部的几个大型场所。但从大约一年前开始，他们便开始将这些武器分散到20多个主要地点。

Unit 450 also started using dozens of smaller sites. The U.S. now believes Mr. Assad's chemical arsenal has been scattered to as many as 50 locations in the west, north and south, as well as new sites in the east, officials said.

另外，Unit 450也开始使用20来多个较小的存放场所。官员们说，美国现在认为，阿萨德的化学武器被分散到东西南北多达50个场所，其中东边的场所是新建的。

The U.S. is using satellites to track vehicles employed by Unit 450 to disburse the chemical-weapons stocks. But the imagery doesn't always show what is being put on the trucks. 'We know a lot less than we did six months ago about where the chemical weapons are,' one official said.

美国正利用卫星跟踪Unit 450分散化学武器所用的车辆。但图片并不总能显示卡车上具体装了什么。一位官员说，对于那些化学武器存放在哪里的问题，我们现在的了解大不如六个月前。

The movements, activities and base locations of Unit 450 are so sensitive that the U.S. won't share information with even trusted allies in the opposition for fear the unit would be overrun by rebels, said current and former U.S. officials.

美国现任和前任官员说，Unit 450的行动、活动和基地位置属于非常敏感的信息，美国甚至不会将其与该国信任的叙利亚反对派盟友共享，因为担心反对派会打垮该组织。