Ethiopia has restricted social media and messaging platforms ahead of rival planned rallies following a split in the popular Orthodox Church.
The row has caused deadly violence and began last month when some clerics accused the main church of ethnic discrimination, which it denies.
The authorities banned protests by both sides due to take place on Sunday.
Some supporters of the main church angrily accuse the authorities of backing the breakaway group.
They had vowed online to defy the ban and go ahead with their rally as a show of strength for the Orthodox Church, which is one of the oldest in sub-Saharan Africa and one of the few in the region to exist before the arrival of European missionaries.
There are fears of a complete internet shutdown in the coming days. It is a tactic commonly used in the country – which has a population of 115 million – though rarely in the capital, Addis Ababa.
Some areas of the northern region of Tigray, where a brutal two-year conflict came to an end in November after a peace deal brokered by the African Union (AU), remain without access to the internet.
Netblocks, an organisation that monitors internet access, said the current restrictions are affecting Facebook, Messenger, Telegram and TikTok.
Those with virtual private network (VPN) software can get on to those sites, but a total shutdown would prevent that.
London-based VPN research firm TOP10VPN said demand for VPNs in Ethiopia skyrocketed by 1,430% on Friday.
The authorities have also closed schools on Friday as tension mounts in the deeply religious society – and there are concerns the situation may escalate further.
The authorities are also preparing for the annual AU summit, which is due to be held next week.
It will be the organisation’s first meeting since the Tigray deal was signed and the government will be anxious to avoid unrest in Addis Ababa, which is where the AU’s headquarters is based.