Baghdad (CNN) -- Iraqi authorities executed four al-Qaeda senior leaders after they were convicted of terrorism, the nation's Ministry of Justice reported Monday. Manaf Abdul-Raheem Abdul-Hameed al-Rawi, the leader of the so-called Islamic State of Iraq in Baghdad, was among the four who were executed by hanging Monday morning. The executions came on a day when a suicide bomber drove an oil tanker into a police station in central Tikrit, killing at least nine people and wounding 20, an official with Iraq's interior ministry said. Tikrit is about 160 kilometers (100 miles) north of Baghdad. It's a predominantly Sunni town located in Salaheddin province and is the hometown of former Iraqi leader Saddam Hussein.
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NEW: Four al-Qaeda senior leaders are executed in Iraq
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NEW: Prime Minister al-Maliki declines to discuss security in an open session of parliament
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Twelve people die in a suicide attack and shootings, including nine in Tikrit
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163 Iraqi civilians, policemen and soldiers died in March
In @placeholder, two policemen and a civilian were shot dead by gunmen in a pair of incidents, the Interior Ministry said.