The capital of China's Xinjiang region, Urumqi, has been rocked by more protests, following a deadly clash Sunday that left more than 150 people dead.

There were at least two demonstrations in Urumqi Tuesday. One involved hundreds of mostly Uighur Muslim women in traditional headscarves, who scuffled with armed police.

Many of them screamed for Chinese authorities to release their husbands or children. Their relatives are among more than 1,400 people, mostly Uighurs, who have been detained following a violent demonstration Sunday.

One woman protester said her situation has become tragic.  She says she would rather die than live without her husband.

Later Tuesday, police in Urumqi fired tear gas to disperse hundreds of Han Chinese protesters who waved wooden sticks and metal pipes in the air.

The Han are the country's dominant ethnic group. The clashes have largely been between the Han and Uighurs, a largely Muslim minority group that shares linguistic and cultural bonds with Central Asia.

In Beijing, Chinese Foreign Ministry spokesman Qin Gang repeated his government's accusation that "foreign separatist forces" who want to create an independent Xinjiang are behind the unrest.

Qin says the foreign forces "planned" and "masterminded" Sunday's incident. He especially pointed his finger at exiled Uighur businesswoman Rebiya Kadeer.

Kadeer was jailed in China and now lives in the United States. She heads the World Uyghur Congress.

The Chinese spokesman also acknowledged that in recent days, authorities in Urumqi have been interrupting two main sources of communication.

He says initial investigations into the incident find that foreign forces have used the Internet and cell phones to, in his words, "instigate and incite the violence." So, he says, local authorities have taken measures, according to law, to safeguard social stability. 

The unrest is reported to have spread to cities in other parts of Xinjiang, in China's far west, including the city of Kashgar, near the border with Pakistan.

Xinjiang, like Tibet, is one of the most politically sensitive regions in China. Nearly half of the region's 20 million people are Uighur. Many complain that Han Chinese discriminate against them and benefit from Chinese government policies in Xinjiang, at their expense. They also say the government tries to suppress their religion.