URUMQI - At least 200 people staged a fresh protest in China's Urumqi city in front of foreign reporters on Tuesday to demand the release of detained relatives, two days after deadly riots here.

The relatives, all Uighurs, approached the reporters in the capital of Xinjiang with their fists in the air, tears rolling down their faces, and then engaged in a tense stand-off with police, an AFP reporter said.

"I'm here to demand my husband be returned," said one woman who gave her name as Maliya, as she held the hand of her crying seven-year-old son.

She said police burst into their house on Monday and took her husband away.

Maliya insisted her husband took no part in Sunday's unrest.

"We were at home when it happened," she said.

The protesters, mostly women and children, were emboldened by the presence of six bus-loads of foreign reporters on a government-sponsored trip to Urumqi after riots on Sunday left at least 156 people dead and over 1,000 injured.

"Film this," one protester said, while others made signs to mimic the action of taking a photo.

Hundreds of police armed with machine guns, shotguns and batons surrounded the protesters, who refused to move. The demonstration started at about 11 am (Singapore time 11 am) and by 11.40 the stand-off was continuing.

The police had also brought in German Shepherd dogs.

The unrest on Sunday saw Muslim Uighurs, who have long complained about repression under Chinese rule, take to the streets.

Chinese authorities have accused exiled Uighur leaders of orchestrating the unrest, and state television has shown footage of Uighurs attacking people in the streets, turning over police cars and smashing shops.

But exiled Uighur leaders have said Chinese security forces over-reacted to peaceful protests and fired indiscriminately.