BAGHDAD — Three separate explosions rocked Baghdad today, killing at least 25 people and wounding dozens of others, police said.

A suicide bomber crashed into an Iraqi police checkpoint at an entrance to the Sadr City neighborhood — the Iraqi capital's largest Shiite slum — killing 10 people and wounding 15, police said.

Elsewhere, a parked car exploded near a private hospital in the central neighborhood of Karradah — killing 11 people and wounding 13, police said. The blast damaged the Abdul-Majid hospital and other nearby buildings.

The third explosion was from a bomb left on a minibus in the northwestern Risafi area, killing four people and wounding six others, police said.

CAIRO, Egypt — Failure in Iraq would unleash sectarian strife and extremism and would be felt first in the Middle East, Defense Secretary Robert Gates said today.Speaking to a U.S. Chamber of Commerce luncheon on the third day of his Middle East travels, Gates exhorted Arab countries in the region to use their influence to dampen the insurgency and encourage political reconciliation in Iraq."Whatever disagreements we might have had over how we got to this point in Iraq, the consequences of a failed state in Iraq — of chaos there — will adversely impact the security and prosperity of every nation in the Middle East and the Gulf region," Gates said.He warned that while some who disagree with the war may be cheering for failure in Iraq, "these sentiments are dangerously shortsighted and self-destructive."The initial effects of failure, he said, would first be felt in Middle East capitals and communities "well before they are felt in Washington an in New York."Gates' speech came in the midst of visits to military and political leaders in the region, where he urged them to do what they can to spur reconciliation efforts in Iraq and involve the Iraqi government more actively in the political discourse in the Middle East.Gates reaffirmed the U.S. commitment to Iraq and to protecting allies in the area — while also alluding to the raging debate between the Democratically controlled Congress and the Bush administration over bringing an end to the war.