Saudi Arabia, Riyadh: Hanging of four Shia Muslims in Saudi Arabia, hundreds or thousands of the minority sect have marched nightly in protest, and their anger could herald wider unrest since Saturday. The hanging of one of them, dissident cleric Sheikh Nimr al-Nimr, caused an international crisis as Shia Iran and its allies responded angrily, but it also caused upset in his home district of Qatif, where many saw his death as unjustified.

“People are angry. And they are surprised, because there were positive signals in the past months that the hanging would not take place. People listen to his speeches and there’s no direct proof he was being violent,” a Qatif community leader said by phone.

The protests in Qatif, an almost entirely Shia district of about a million people in the oil-producing Eastern Province, have been mostly peaceful, though a fatal shooting and gun attacks on armoured security vehicles have also taken place. Qatif is located near major oil facilities and many of its residents work for the state energy company, Saudi Aramco. On Thursday night, past incidents of unrest have not led to attacks on the oil industry, but a bus used by Aramco to transport employees was torched after a protest.

Footage of marchers shouting “down with the Al Saud” and other anti-government slogans, corroborated by witnesses contacted by Reuters, is circulating on social media along with video clips showing shots fired at armoured cars. “I did not hear shooting last night, but I heard it a lot on the two nights before,” a resident of Nimr’s home village, al-Awamiya, told Reuters by phone. Like others Reuters spoke to in Qatif, he asked that his name be withheld.

Saudi Arabia only permits foreign news media, including Reuters, to visit Qatif if accompanied by government officials, which it says is to ensure journalists’ safety. Whether the protests — and sporadic attacks on police — escalate may depend on whether the security forces continue an unspoken policy of allowing peaceful demonstrations until they die down, or crack down with force, say locals.

Government supporters say it depends rather on whether Tehran uses links to local activists, which both Iran and many Qatif residents deny exist, to stage attacks in retaliation for Nimr’s execution and Riyadh’s cutting of diplomatic ties.