By Saud Mahsud DERA ISMAIL KHAN, Pakistan (Reuters) -Militants stormed a police station in northwest Pakistan on Tuesday, killing four security officials and wounding several more, officials said, in a bomb and gun attack for which a Pakistani Taliban group claimed responsibility. The attack in the district of Dera Ismail Khan, on the edge of the lawless tribal regions bordering Afghanistan, wounded 28 people, said Aizaz Mehmood, an official of the state-run rescue service. “We are still hearing gun shots,” he added. The militants rammed a vehicle laden with explosives into the main gate of th…