Witnesses say police have stormed a protest camp in the southern Yemen port city of Aden, where thousands are calling for the ouster of the country's longtime president.
Protesters say police fired tear gas and live rounds. The number of injured remains unclear.
Today's raid is the latest attempt by security forces to put down growing unrest.
Soldiers have set up checkpoints to enforce a ban on carrying firearms in public, even checking for hidden guns inside the ornamental scabbards of traditional Yemeni jambiya daggers.
On March 18, security forces in the capital, Sanaa, killed at least 46 and injured hundreds
in the harshest crackdown yet by President Ali Abdullah Saleh against monthlong protests against his 32-year rule.
Also today, two prominent members of Yemen's ruling party resigned in protest after the killing of dozens of antigovernment protesters.
Nasr Taha Mustafa, head of the state news agency, said he had resigned from his post and the party in protest over the killings of up to 42 protesters by rooftop snipers in the capital.
compiled from agency reports