Government forces in Yemen have continued firing shells at a protester camp in the capital, witnesses say.
Explosions rocked Sanaa all night, and at least two people had died in the shelling.
Government forces launched a crackdown on the protesters on Sunday, killing more than 50 people in two days.
Groups of protesters have occupied various parts of the capital for most of the year, calling for the ousting of President Ali Abdullah Saleh.
Mr Saleh, who has ruled the country for more than three decades, has been in Saudi Arabia since June, when he was seriously injured in a rocket attack on his presidential compound.
