Secretary-General Ban Ki-moon Wednesday called for an independent investigation of all killings that occurred during the demonstrations that have rocked Syria in recent weeks and reiterated his call for an end to the violence and mass arrest of people taking part in peaceful protests, according to a UN report.

The investigations should include the alleged killing of military and security officers, Ban said during a telephone conversation with the Syrian President Bashar al-Assad. The Secretary-General stressed the need to respect the human rights of the Syrian people.

"The Secretary-General emphasized that the humanitarian needs of the population should be urgently met," according to an information note released by his spokesperson.

Ban expressed deep concern over the humanitarian impact of the violence on a number of Syrian towns and urged Mr. Assad to immediately grant access to the United Nations to assess the needs of the affected civilians.

"The Secretary-General appreciated President Assad's willingness to consider such an assessment to Deraa," according to the information note.

The city of Deraa in southern Syria has been at the demonstrations calling for political reform, and has borne the brunt of the violence.

Ban also encouraged the full and immediate implementation of all the reform measures announced by the Syrian Government and emphasized the importance of engaging in genuine, inclusive dialogue and comprehensive reform.

Last week, the United Nations Human Rights Council voted for a mission to be sent to Syria to investigate alleged violations of international human rights law and crimes committed against civilians. The violence has reportedly claimed the lives of hundreds of people.