12月20日，伊拉克当局逮捕了50名19日纳杰夫汽车炸弹袭击事件的涉案嫌疑人，并怀疑他们袭击的目标是什叶派宗教领袖西斯塔尼。外电报道如下：Police rounded up dozens of suspects on Monday after twin suicide car bombings killed 66 people in Iraq's Shi'ite holy cities, attacks that intensified fears of sectarian violence during elections on Jan. 30.

Preparing for the poll, officials staged a lottery to choose the order for parties and blocs to appear on the ballot paper, holding the event in a closely guarded building that was once part of Saddam Hussein's palace complex.

In Najaf, scene of the deadlier of Sunday's coordinated attacks, the governor said police had seized 50 suspects. Police detained five more in Kerbala, site of the other blast, but were cautious about saying they were close to the culprits.

Round up表示“围捕，使集拢”，此外还有“四舍五入”的含义，等于round down。相关的词组还有round off（用四舍五入化为整数，缩减小数位），例如：3.1415926 gives 3.14 when rounded off to 2 decimal places.（将3.1415926缩减成2位小数就成了3.14。）