Iraqi forces try to encircle Mosul's IS-held Old City

Displaced Iraqis make their way to get into Hamam al-Alil camp, on a rainy day, south of Mosul, Iraq March 16, 2017. REUTERS/Suhaib Salem

MOSUL, Iraq (Reuters) - Heavy rain slowed Iraqi government forces battling Islamic State on Thursday around Mosul's Old City, where militants holed up in narrow alleyways and homes resisted with sniper fire, suicide attacks and car bombs.

Troops from the federal police and elite Rapid Response units were about 500 m (yards) from the al-Nuri Mosque from where Islamic State leader Abu Bakr al-Baghdadi declared a caliphate spanning Iraq and Syria in 2014.