The death toll from two bomb blasts in the Syrian city of Homs on Sunday reached 46 including at least 28 civilians, the Britain-based Syrian Observatory for Human Rights said.

The Observatory said the attacks, which hit the city's central Zahra district, were among the biggest blasts to hit a government-held area in Homs in the five-year-old civil war.

The governor of Homs was quoted by Syrian state television as saying the death toll was 25 people. State TV initially said 14 had been killed.

A bomb attack claimed by Islamic State last month in Homs in the west of the country killed at least 24 people, the city's governor said at the time, as government forces took back some Islamic State-held villages in Aleppo province in the north.

Sunday's attacks also came a day after government advances against Islamic State. There was no immediate claim from the group, however.

Another bomb attack in December which killed 32 people took place following a ceasefire deal that paved the way for the government to take over the last rebel-controlled area of the city, which was a centre of the 2011 uprising against President Bashar al-Assad.