Clutch your iPhone a little tighter on the Metro.

Metro Transit Police officials said Friday that there’s been an increase in iPhone 6 thefts over the past month on the blue, orange and silver Metro lines, the Washington Post reported. While cellphone thefts have been on the rise over the past year, the most popular cell phone to be stolen is the iPhone 6, according to the report.

Metro officials have cited six thefts that they believe are related. Most of the incidents were reported both aboard trains and stations, and specifically around Eastern Market and the easternmost stations of the orange and blue lines.

Thieves often take the phones out of users’ hands and usually when the train stops at a station, making for an easier getaway.

Metro police recommend riders not use their phones near train doors and escalators, and to activate tracking services on the phone so officers can try to recover it if it is stolen.