In Al-Qatif, a large and predominantly Shiite city on the coast of Saudi Arabia's Eastern Province, renewed clashes between police and protesters erupted on Sunday, injuring both local policemen and activists.
The protests began after Saudi security forces arrested two elderly men on Sunday in order to pressure their sons -- who are both activists -- to surrender to police.
But upon arrival at the police station, one of the men, who was 72 years-old, had a heart attack.
This video reportedly shows an ambulance leaving the local police station with the man, who was said to be named "Haj Al-Zayid".
When protester and activists heard news of the heart attack they surrounded the police station, throwing rocks and other objects into the compound -- as you can see in this video, also uploaded to YouTube.
When human rights activists tried to enter the station on Sunday to talk to the police, they too were arrested.
On Monday, reports emerged online and on Twitter that crowds of armed men with guns and molotov cocktails stormed the station once again.
This video documents some of what happened on Monday, which left 11 policemen injured.
Since February, Saudi Arabia has seen sporadic protests across the country. For decades Shiites have complained of discrimination as many who follow the Wahabi form of Islam, which is the dominant faith in the country, view Shiites as heretics.
These recent clashes mark the biggest protests in the country since similar protests took place in March, which were quickly quashed by security forces.
Saudi Arabia's interior ministry said that an unnamed foreign country was responsible for the unrest, which in the Gulf often is a coded reference to Iran.
The interior ministry also confirmed that 14 people had been injured and called on protesters to "clearly identify their loyalty to Allah and their nation or to that of the other country."
They also warned that they would use an "iron fist" against anyone who compromises the security of Saudi Arabia.