The supreme and district courts of Puerto Rico and the respective judges thereof may grant writs of habeas corpus in all cases in which the same are grantable by the judges of the district courts of the United States, and the district courts may grant writs of mandamus in all proper cases.

No suit for the purpose of restraining the assessment or collection of any tax imposed by the laws of Puerto Rico shall be maintained in the United States District Court for the District of Puerto Rico.