dude, it got to customs on friday. customs may not work on saturday or may be lazy, like normal, and not have scanned the package on exit. monday was a holiday so find something else to do for a few days and wait. i doubt they were seized! packages miss scanning all the time so tracking is never absolutely correct.
Every time Ive gotten stuff from out of country, it sat in customs for at least 5 working days, that's not including weekends and holidays. Think about how many packages get imported every day, they cant sort through all that instantly. Give it at least another week before you begin to worry.
Its been 5 days since your order was sent out, usually stuff from China takes almost a month, be pleased its already in the US and will not be much longer.