RIYADH (Reuters) - Saudi Arabia warned potential protesters on Saturday that a ban on marches would be enforced, signalling the small protests by the Shias in the oil-producing east would no longer be tolerated. "The kingdom's regulations totally ban all sorts of demonstrations, marches, sit-ins," the interior ministry said in a statement, adding security forces would stop all attempts to disrupt public order. Inspired by protests in other Arab countries there have been Shia marches in the past few days in the east and unconfirmed activist reports of a small protest at a mosque in the Saudi capital Riyadh on Friday. The US ally has not faced protests of the scale that hit Egypt and Tunisia that toppled veteran leaders, but dissent has built up as unrest has spread in Yemen, Bahrain, Jordan, Libya and Oman. More than 17,000 have backed a call on Facebook to hold two demonstrations this month, the first one on Friday. For about two weeks, Saudi Shias have staged small protests in the kingdom's east. Shia protests in Saudi Arabia started in the area of the main city Qatif and its neighbour Awwamiya.