WASHINGTON (Reuters) - U.S. President Joe Biden on Wednesday signed into law a bill calling for more sanctions and other punitive measures against the government of Nicaraguan President Daniel Ortega, who extended his grip on power in an election that Washington has denounced as a sham, the White House said.

       The arrests of dozens of opposition politicians, including presidential hopefuls, all but guaranteed Ortega, a former Marxist guerrilla, would win a fourth consecutive term in Sunday's election, tightening his grip on the Central American nation while facing increasing international isolation.

       (Reporting by Matt Spetalnick; Writing by Mohammad Zargham; Editing by Chizu Nomiyama and Tim Ahmann)