Syrian forces killed at least 29 people on Thursday in rocket and mortar bombardments of several districts of Homs, the heart of a revolt against President Bashar al-Assad, activists and opposition sources said.

They said the bombardments centred on the Baba Amro, Inshaat, Khalidiya, al-Bayyada and Jouret al-Shayyah districts of the city of one million people.

Earlier, the British-based opposition Syrian Observatory for Human Rights said 12 people had been killed in Baba Amro and another in Khalidiya.

Activists and residents have reported hundreds of people killed over the last week in the heaviest assault on the city since an uprising against Assad erupted last March. The revolt started with street protests but has become an armed insurgency in many parts of the country.

Authorities say they are fighting foreign backed terrorists in Homs.

(Reporting by Dominic Evans and Khaled Oweis; Editing by Angus MacSwan)