Fresh spurt in clashes in the Syrian city of Homs witnessed more than 13 soldiers killed and more tanks were pressed into service to bring the situation under control.
Ten civilians were killed and three were seriously wounded in the attack, said reports.
Rallies have been held since mid-March which spread all over the country including the capital Damascus. The troops, however, failed to quell the protests.
The Syrian government has insisted that the rioters surrender before May 15. Reports said that more than 800 people have turned themselves in till date.