WASHINGTON — US Vice President Joe Biden on Wednesday urged lawmakers to pass President Barack Obama's jobs proposals, warning that crime rates have spiked as more and more police are laid off.

"In Flint, Michigan, they cut their force in half, murder rates have doubled in the last year," Biden said on Capitol Hill before a gathering of police officers, firefighters and teachers.

"In many cities the result has been -- and it's not unique -- murder rates are up, robberies are up, rapes are up."

Obama on Monday launched a three-day bus tour across key 2012 swing states Virginia and North Carolina to make a new pitch for the jobs scheme, which was blocked by the Senate, as he now seeks to pass the $447 billion plan in chunks.

"Forty-nine senators said we're not even allow you to debate this issue," Biden said. "What I want and my colleagues want is to vote on it piece by piece."

"The first piece is a critical piece -- it's about firefighters, law enforcement officers, first responders and teachers," he said, hailing the "people who save our lives and give our children a chance to have good lives."

"This is an emergency," the vice president said, criticizing the fact that 300,000 teachers have been laid off in the past 18 months.