MOSCOW (Reuters) - Russia's Defense Ministry said on Friday a new objective of Russian forces in Syria was to provide humanitarian aid.

Russian air force planes have delivered 22 tonnes of aid in the region around the eastern Syrian city of Deir al-Zor, a ministry official said in a televised briefing.

The British-based Syrian Observatory for Human Rights said a Russian cargo plane accompanied by several war planes, dropped aid to several government-held neighborhoods in the city.

The Observatory said that government-held areas in the city had been under siege by Islamic State fighters for more than a year. It said that at least 250,000 people were living in dire conditions lacking food and medicine.

The United Nations says there are some 450,000 people trapped in around 15 siege locations across Syria, including in areas controlled by the government, Islamic State and other insurgent groups.

This week, two convoys of aid supplies were delivered to a rebel-held town of Madaya near the border with Lebanon where local relief workers reported 32 deaths of starvation in the past month.

"Let us not forget that in addition to Madaya, across Syria there are 14 other Madayas and these are locations where different parties to the conflict have been using siege as a tactic of war, depriving children and innocent civilians from accessing life-saving supplies and services," UNICEF spokesman Christophe Boulierac said.

(Reporting by Jack Stubbs; additional reporting by Mariam Karouny in Beirut; Editing by Alexander Winning and Alison Williams)