Turkey has started hijacking net addresses as it steps up attempts to block access to social media, the BBC reported.
Addresses belonging to Google, Level 3 and OpenDNS have all been hijacked by order of the Turkish government.
The hijack means that people using those addresses to reach Twitter or YouTube can no longer get through.
Net monitoring firms said the hijack was “concerning” and would let the government log who was trying to get round its controls.
The addresses that have been hijacked are for domain name servers – computers which list where websites are on the net.
One of the first ways Turkey blocked access to Twitter and YouTube was by getting ISPs to stop their domain name servers directing people to the two sites. It took action against the microblogging site and video service after both were used to leak information embarrassing to the government.
The government said it also imposed the blocks because the sites were spreading misinformation in the run-up to local elections which took place over the weekend.