By Tom Perry and Seyhmus Cakan BEIRUT Leba**n/DIYARBAKIR Turkey (Reuters) - A new offensive by al Qaeda offshoot the Islamic State on Kurdish-held areas of **rthern Syria has triggered a regional call for arms from the Kurds, and Turkish Kurds are coming to their aid. The war in Syria has already drawn in an array of regional players and the regional Kurdish involvement complicates an increasingly fragmented scene across Syria and Iraq, where the Islamic state took control of large areas last month. The predominantly Kurdish city is k**wn as Kobani to the Kurds who have controlled it since 2012, part of an expansion of their influence following the collapse of central government control that has allowed for closer ties with Kurds across the border.