Turkey's deputy prime minister said Monday the armed forces could be called up if needed to help quell popular protests that have swept Turkish cities in the last two weeks, the first time the possibility of a military role has been raised. 

Bulent Arinc made the remarks in Ankara, where 1,000 striking trade union workers faced off briefly against police backed by several water cannon, before police retreated and the crowd left. 

In Istanbul, the cradle of protests that have presented Prime Minister Tayyip Erdogan with the greatest public challenge to his 10-year leadership, several hundred union members also marched in sympathy with anti-government demonstrations.