Four detained security guards of former state minister for Port and Shipping Nabeel Gabol have been released, Dunya News reported Thursday.Earlier, police have raided the house of State Minister for Ports and Shipping Nabeel Gabol and arrested 12 security guards just hours after he resigned from his post. Nabeel said that these were the pressure tactics being used against him. Earlier, State Minister for Ports and Shipping Nabeel Gabol tendered resignation from his post. He sent his resignation to the Prime Minister and the PM spokesman had confirmed it. According to PM House, Nabeel Gabol sent resignation due to personal reasons. Nabeel Gabol said that he has no differences with his party (PPP). He said that he was a powerless minister. He said that he will not keep ministership even if the PM doesnt accept his resignation.