A small protest also took place after midnight in the northern Baghdad district of Al-Shula amid a heavy deployment of security forces, a security source told AFP.
His Highness the Amir told the Iraqi premier that Kuwait stands ready to assist its neighbor to overcome the current turmoil, emphasizing that stability in Baghdad is among Kuwait's chief concerns. "The reported video claims that there is violence near an oilfield on the Iraqi-Kuwaiti border is completely divorced from reality", the ministry's security media department said in a statement.
On Saturday evening, Abadi announced investment worth $3 billion for Basra province, as well as pledging additional spending on housing, schools and services.
"Elsewhere in Basra, protesters also forced authorities to close the vital Um Qasr port on the Persian Gulf, and planned to march to the border crossings with Kuwait and Iran, he said".
The internet had been out of service across the country for 48 hours.
Hundreds of people tried to storm a government building in Basra on Saturday night.
Around noon on Sunday, Basra anti-riot police fired water cannon and tear gas to disperse the protesters, said Sadiq Saleh, one of the demonstrators.
Several civilians and policemen were also injured in clashes around the governor's home in the city of Nasiriyah, a medical source said. The clashes, including hand-to-hand combat, erupted when the demonstrators gathered outside the governor's office and pelted security forces with stones.
On Saturday, protesters had set alight Badr s headquarters in Basra, prompting authorities to impose an overnight curfew across the province.
He said security forces had fired into the air in an attempt to disperse angry protesters.
A sizeable contingent from Saraya al-Salam, a paramilitary force loyal to prominent Shiite cleric Moqtada Sadr who won May elections, also deployed in the streets of Najaf.
Protests in the city of Basra, the provincial capital and Iraq's second-largest city, are not unusual in scorching summer weather but they boiled over last Tuesday, when security forces opened fire, killing one person and wounding five.
At least two protesters were killed in southern Iraq as protests against economic hardship and corruption spread from the port of Basra to other parts of the country. The unrest comes as Iraq struggles to rebuild after a devastating three-year war against Islamic State group jihadists, and with the country in political limbo following May elections.
The official unemployment rate in Iraq is 10.8 percent, but that figure doubles among the country's large young population.
Oil exports from Basra account for more than 95 percent of OPEC producer Iraq's state revenues.
Iraqi Prime Minister Haider al-Abadi arrives for the second day of a North Atlantic Treaty Organisation summit in Brussels, Belgium, July 12, 2018.
It was seventh day of unrest in southern cities regarding poor services.
Earlier on Sunday, Jordan's state airline said it had suspended four weekly flights to Iraq's holy city of Najaf due to the "security situation at its airport".