* Fourth day of protest smaller, but signals wider discontent
* Protesters ask who gave police orders to fire on demonstrations
By Robin Paxton
AKTAU, Kazakhstan, Dec 20 (Reuters) - Sacked oil workers in Kazakhstan demanded on Tuesday to know who ordered police to fire on protesters during clashes that killed at least 15 people in the Central Asian state's worst violence in decades.
About 100 demonstrators, braving frost and strong winds, confronted dozens of riot police in Aktau, capital of the western, oil-producing Mangistau region where protests in two nearby towns have turned into bloody clashes in recent days.
Violence have not spread beyond the region but political analysts say the protests suggest that broader public pressure is mounting for President Nursultan Nazarbayev to relax the authoritarian system he has built up since Soviet times.
"We demand to know: Who gave the order to shoot at oil workers?" said Nurzhan Imangaliyev, 27, who was laid off by oil company Karazhanbasmunai (KBM) in May after he and thousands of others joined a strike across Mangistau to demand higher wages.
"Why did our relatives die as a result of a peaceful, social argument?"
On the first working day after four days of public holiday, the rally was smaller than those over the long weekend, when about 500 protesters had gathered daily in Aktau's Concord Square.
Many of the protesters took shelter from biting wind against the walls of a Soviet-era apartment block under a poster of Kazakhstan's futuristic new capital Astana, a prestige project for Nazarbayev, a former member of the Soviet Communist Politburo who has run Kazakhstan for more than two decades.
At least 14 people were killed in clashes between oil workers and police in the oil town of Zhanaozen on Dec. 16, the 20th anniversary of Kazakhstan's independence from Moscow. Another was killed in the nearby village of Shetpe on Dec. 17.
The Kazakh authorities have said police only opened fire after being attacked by "criminal elements" or "hooligans" and that the lives of civilians were threatened.
STATE OF EMERGENCY
Kazakh Interior Minister Kalmukhanbet Kasymov told a government meeting on Tuesday that 110 people had been wounded in the clashes, including 17 police officers.
Nazarbayev, a 71-year-old former steelworker who declared a state of emergency in Zhanaozen, has blamed "hooligans and criminal elements" for violence in which he said 46 buildings had been damaged. Private houses, shops and banks, as well as cars and buses were torched, and bank ATM machines were looted.
Movement is now limited in and around Zhanaozen, where a curfew is in force. Reuters journalists who travelled to Zhanaozen with a police escort on Monday saw armoured personnel carriers and riot police patrolling the town of 90,000 people.
In Aktau on Tuesday, Talgat Imambayev, 38, said telephone contact with his family in Zhanaozen appeared to have been cut: "We want to be in touch with Zhanaozen. I myself don't know if my relatives are alive or dead."
The Kazakh prosecutor-general's office said in a statement on Tuesday: "The situation in the cities of Zhanaozen, Aktau and the village of Shetpe, as well as in general in the region is stable and under the control of law enforcement bodies."
Despite the small number of protesters in Aktau, the daily rallies signal that a pocket of dissent has developed. Nazarbayev enjoys sweeping powers and brooks no opposition. One of his aides said this week there was no risk of an "Arab-style revolution" because Kazakhs supported the president.
In Aktau, not everyone agrees.
"Oil is slavery. Here, there is no democracy," said Baurzhan, another of the sacked strikers from oil firm KBM, which is jointly owned by London-listed KazMunaiGas Exploration Production and CITIC, China's biggest state investment company.
Another laid-off oil worker, a father of four who declined to give his name, said: "They say hooligans did this, but if you hadn't been paid for seven months then you would think about raiding an ATM. The oil workers have mouths to feed."