DENVER - Colorado Democrats gave initial approval to expanding background checks on firearm purchases and setting ammunition limits as the battle over stricter gun laws got under away at the state Capitol.

A House committee voted Tuesday to require background checks on private gun sales and online firearm purchases, and also a limit on high-capacity magazines. Republicans opposed the measures.

Democrats voted to amend the bill that would banhigh-capacity ammunition magazinesof more than 10 rounds and increased that to 15.

The votes came after more than eight hours of testimony from those who say the measures are needed to curb gun violence, and people concerned that their right to bear arms is being restricted.

"We cannot wait for yet another massacre to transpire before we take real action," sister of Sandy Hook victim Jane Dougherty said.

"I fired 13 rounds in defense of my life in a magazine in a pistol that had 16 rounds," gun violence survivor Charles Robles said.

It's the beginning of a long fight on a package of Democratic bills that are responses to the mass shootings at an Aurora movie theater and a Connecticut elementary school.

Several more votes are needed before the bills become law.