BASRA, Iraq (Reuters) - Five protesters were killed and 16 more were injured during a second day of clashes with security forces in Iraq’s main southern city Basra, local health and security sources said.

Twenty-two members of the security forces were also wounded, some by a hand grenade, the sources said, in some of the worst unrest reported during months of protests sweeping the long neglected south, heartland of Iraq’s Shi’ite Muslim majority.

Protesters are angry over electricity outages during the hot Iraqi summer, a lack of jobs and proper government services and entrenched corruption.

Basra residents say salt seeping into the water supply has made it undrinkable and sent hundreds to hospital, proof, they say, that infrastructure has been allowed to collapse in the part of the country that produces most of its oil wealth.

As the clashes continued to unfold, Iraqi Prime Minister Haider al-Abadi convened an emergency cabinet meeting to discuss the unrest and ordered the Interior Ministry to conduct an immediate investigation into the protests, state media reported.

Hundreds of people gathered at local government buildings, hurled petrol bombs and stones and attempted to block roads leading to the building for a second night. Some protesters stormed one of the provincial government buildings and set it alight.

Security forces fired live rounds in the air as well as teargas to try to disperse the crowd, local sources said. Smoke could be seen billowing from the outer perimeter of the provincial government headquarters, where many had gathered earlier on Tuesday to mourn a protester who died on Monday night, Yasser Makki.

The crowds near the government buildings had largely dispersed by 11 p.m., after a citywide curfew was imposed by the city’s security officials.

Iraq’s second biggest city, Basra is a stronghold of Moqtada al-Sadr, a Shi’ite cleric and former leader of anti-American sectarian militia who has recast himself as an anti-corruption campaigner.

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In a tweet, Sadr appeared to back the protesters, condemning the tactics used by some members of the security forces against who he said were “unarmed demonstrators who only want to live with dignity”.

The public anger has swelled at a time when politicians are struggling to form a new government after an inconclusive parliamentary election in May. Iraq’s top Shi’ite cleric Grand Ayatollah Ali al-Sistani has expressed support for the protests.

Earlier on Tuesday, mourners carried Makki’s body near the building, chanting “Yasser’s blood will not be lost”. They damaged the gate of the local government building but were dispersed by security forces using teargas before they could enter it.

Earlier on Tuesday, Abadi had ordered an investigation into Makki’s death during his weekly press conference.

“Our orders are clear in banning the firing of live ammunition during demonstrations,” Abadi said.

He suspended the electricity minister last month, saying his government had begun punishing those responsible for poor services in Basra.