Iraq's oil minister said Monday he resigned after the government last week gave him a forced vacation and replaced him with Deputy Prime Minister Ahmad Chalabi following criticism about fuel price increases.

Ibrahim Bahr al-Uloum said he quit because the government raised fuel prices by nine times on Dec. 19, a decision he had strongly criticized.

"This decision will not serve the benefit of the government and the people. This decision brings an extra burden on the shoulders of citizens and caused an increase in the prices of all essential materials. It also caused a reaction on the Iraqi streets," al-Uloum said.

The price increases and the mid-December closure of the country's biggest refinery led to protests in many cities around Iraq and riots in northern oil-rich Kirkuk, where police shot and killed four protesters during unrest Sunday.

Officials at the Beiji refinery reopened it Sunday nearly two weeks after shutting it down because of insurgent threats to kill drivers of fuel trucks.

"We started to supply the tankers with oil products after the government promised to secure them along the highways," said Ahmed Ibrahim Hamadi, the director of distribution at the refinery.

The decision came after the Iraqi army sent more troops to guard the tanker trucks that supply the capital, including its main storage facilities in Dora, and to other Iraqi cities.

"Well-equipped and developed Iraqi army and police forces are guarding all the tankers which are trucking oil products from Beiji refinery to Dora, to Baghdad and other provinces," said Maj. Gen. Abdul Aziz Mohamed-Jassim, director of the Defense Ministry's operations room.