Donald Trump stands firm on proposed US travel ban for Muslims

Republican front-runner Donald Trump has stood firm over his provocative call for banning Muslims from the United States as his party’s presidential candidates pushed their own plans for fighting Islamic State (IS) militants.

The Las Vegas debate was dominated by national security, reflecting the reshaping of the 2016 presidential contest by the recent attacks in Paris and San Bernardino, California.

Hours before the debate began, officials in Los Angeles closed all schools after an emailed threat that was later deemed a hoax.