Riot police

NBC News (MOSCOW) — Riot police moved in at a rally in Moscow Saturday afternoon as thousands of people took to the streets to voice their discontent with the government of Vladimir Putin, just days before his inauguration for a fourth presidential term.

Riot police on Tuesday set up a cordon around the historic building of Athens Polytechnic in downtown Exarchia after coming under attack from self-styled anarchists.

The clashes started after a group of a few dozen self-styled anarchists broke away from a May Day rally in the city center and took refuge in the university building in order to launch the attack on police.

Concerns have peaked over tensions on the Aegean islands following clashes between residents of Lesvos and migrants in Mytilene port which led to several injuries. 

Around 10 people were rushed to hospital on Lesvos on Tuesday night following violent clashes between rival groups in the Moria refugee and migrant camp, Ekathimerini reported.

Riot police were called in to quell the unrest, which reportedly broke out between rival groups of Iraqi and Afghan nationals and resulted in several small fires being set.

Riot police had to use tear gas on Tuesday to push back protesters with the PAME union trying to rush their vans after tearing at the metal shutters in front of the Labor Ministry in downtown Athens.

Greek police have used stun grenades and tear gas to disperse a brief but violent altercation between PAOK supporters and members of Athens's Pakistani community.

Police say there have been no serious injuries and no arrests.

Riot police units stationed in Athens's Exarchia district were attacked by unknown assailants with Molotov cocktails in the early hours of Friday, authorities said.

The incident occurred shortly after 3 a.m. outside the offices of PASOK on Harilaou Trikoupi Street.

No one was injured in the attack.

One person was briefly detained, questioned and released.

A crackdown by police in the area of Menidi, north of Athens, at the site of a former military barracks called Kapota, led to the arrest of 16 people on charges ranging from drugs and arms possession to fraud.

Riot police units stationed in the Exarchia district of central Athens were pelted by petrol bombs hurled by hooded youths late Thursday night.

16 people were detained and later released as there was no evidence linking them to the incidents.

Over 300 people of Afghan and Syrian origin were evacuated from an Istanbul neighborhood on May 16 amid rising tension after the killing of a local man by a foreign resident on May 14, Doğan News agency has reported.