The Tainan city emergency center says the death toll in Saturday's earthquake has climbed to seven, including an infant and a small child. Facebook has activated its "safety check" feature for Taiwan that allows users to let their friends and loved ones know they're safe. Facebook chairman and CEO Mark Zuckerberg says in a posting, "My thoughts are with everyone in Taiwan and across our global community affected by this disaster." The Tainan city emergency response center says the death toll in Saturday's 6.4-magnitude quake has risen to five. According to China's office handling relations with Taiwan, mainland officials have been in touch with their Taiwanese counterparts since shortly after the quake hit the southern city of Tainan. China sent a letter offering rescue assistance if needed, and expressed condolences to those who suffered in the quake. Firefighters and soldiers scrambled to the site of two collapsed residential high-rises with ladders, cranes and other equipment and extracted 221 people from the rubble. Taiwan's official news agency says 34 people were pulled from a 16-story residential high rise that collapsed in Tainan in a 6.4-magnitude earthquake that hit southern Taiwan just before 4 a.m.