A controversial new law that will let students carry concealed guns on campus has come into effect in Texas.
The so-called "campus carry" law allows people aged 21 and older who hold a concealed handgun licence to carry pistols in classrooms and college buildings.
Texas is now one of eight US states to allow students to carry guns on public campuses.
Many higher education officials and students expressed concern the law could discourage students from attending universities in the state.
But supporters of the law argued it was critical to self-defence and upholding constitutional rights.
Republicans in the state said the law could prevent another mass shooting.
Gunmen often targeted gun-free zones such as university campuses and cinemas because they did not meet resistance, Republicans said.
But critics of the new law - which came into effect on the 50th anniversary of a University of Texas mass shooting that claimed 14 lives - said it was an ill-conceived solution that could serve to trigger yet more violence.
Some academics argued the law would also lead to a curtailment of free speech, because students with guns could create an intimidating atmosphere.
Some areas, including sports arenas and chemical labs, were still off-limits even under the new law.
Texan private schools and two-year community colleges have been excluded from the new laws until next year.