Gunmen in plainclothes are randomly shooting people in the streets of the besieged Syrian city of Hama and families are burying their loved ones in gardens at home for fear of being killed themselves if they venture out to cemeteries, a resident says.

Military forces launched an offensive against anti-government dissent in Hama on Sunday and at least 100 people have been killed since, according to human rights groups.

Scores reportedly dead ... smoke is seen near a tank at Al-Bahra roundabout in Hama. Credit:Reuters

Phones, internet and electricity have been cut or severely hampered for days.

The resident told the Associated Press that people are being forced to ration food and share bread to get by during the holy month of Ramadan, when many Muslims fast from dawn to dusk then celebrate with large, festive meals after sundown.