**US Lawmakers Probe Intelligence Sharing After Boston Bombing**
U.S. lawmakers have raised concerns about the sharing of intelligence among federal enforcement agencies, as investigators continue to piece together last week's deadly bombing of the Boston Marathon.
Senator Lindsey Graham said Tuesday that the FBI told him it did not know last year that one of the bombing suspects, Tamerlan Tsarnaev, traveled to Chechnya and Dagestan.
Homeland Security chief Janet Napolitano told the Senate Intelligence Committee that her agency knew of the six-month trip, but that an FBI alert on Tsarnaev had expired by the time he returned.
The FBI had interviewed Tsarnaev in 2011 at the request of Russia, but found nothing to connect him to terrorism at that time.
After a closed-door briefing by FBI officials Tuesday, Republican Senator Susan Collins said there are problems with sharing of "critical investigative information" within and among different agencies.
** Gun Battle in China's Xinjiang Kills 21 People**
Chinese officials say at least 21 people were killed after a gun battle broke out during a police crackdown on suspected criminals in the restive northwestern province of Xinjiang.
State-run media say the clashes began Tuesday, when social workers came across what they called "suspicious individuals" and weapons in a house in western Kashgar prefecture.
When police later arrived to investigate, a gun fight broke out, resulting in the deaths of 15 social workers and police. The report also said six "gang members" were shot dead in the clashes, while another eight were captured.
It called the clashes a "violent terror incident" and said the group was plotting to use the weapons to "launch terror activities".
Xinjiang is an ethnically divided region that sees occasional outbreaks of violence, mainly between the predominantly Muslim Uighur community, government security forces, and the Han Chinese majority.