Activists say Syrian rebels have seized a key military base with artillery stockpiles in the country's east.

The capture of the base in the oil-rich Deir el-Zour province near the border with Iraq follows the seizure of a military airport in the same area last week.

The rebels have been making advances in the strategic province for weeks.

Activist groups and a local fighter told The Associated Press the Mayadeen base fell on Thursday morning after a three-week siege.

The fighter spoke on condition of anonymity because of security concerns.

The Syrian Observatory for Human Rights group says the base was considered the last stronghold for regime forces in the eastern Deir el-Zour area.