The SNP is investigating complaints of sexual misconduct as an urgent meeting of Scotland's party leaders has been called amid allegations of harassment at Holyrood.

The party said two people had raised separate complaints which will be fully investigated.

It comes as a confidential phone-line was set up following "disturbing and deeply concerning" reports of sexual abuse or harassment in the Scottish Parliament.

Human rights lawyer Aamer Anwar has said women ranging from MSPs to interns had made complaints and he accused politicians of maintaining an "abject silence" on the issue.

A parliament spokesman said the number of cases of inappropriate behaviour or harassment brought to the attention of officials over the last five years was "in single figures".

It is understood not all of these related to the conduct of MSPs.

A spokesman for the SNP said: "The SNP has had concerns of this nature raised by two different individuals.

"The individuals and their concerns are unconnected to each other.

"These will be fully investigated but inquiries remain at an early stage.

"We will do nothing to deter people from coming forward and, as such, we will not comment further while investigations are ongoing."

Earlier, First Minister and SNP leader Nicola Sturgeon proposed a cross-party review of parliamentary procedures and said the parliament should be prepared to confront any allegations "head-on".

She said she was not aware of any allegations against SNP MSPs or MPs but added: "I fully expect that we will have concerns coming forward, like every political party will, and we will investigate them, if they come forward, in an appropriate way.

"I don't think any party can assume it's immune from behaviour like this, we want to think we are, but what I'm determined about is that if there are any issues raised associated with the SNP, they will be properly and rigorously investigated."

Ms Sturgeon said the party will "look critically" at the procedures it has in place.

She added: "This is a line-in-the-sand moment where all of us can say, firstly and foremostly, to men that indulge in this kind of behaviour, that it's not acceptable but as organisations - whether that's parliament, parties or workplaces - that we will act and have a zero-tolerance approach to any kind of behaviour like this."

Scottish Conservative leader Ruth Davidson has said her party is reviewing its procedures to provide reassurance for staff.

She said: "The allegations that have emerged in recent days are deeply troubling.

"Sexual harassment in the workplace is wrong and must not be tolerated.

"Those in positions of power, like MPs and MSPs, have an even greater responsibility to lead by example and show respect for all members of staff."

Former Labour leader Kezia Dugdale said it was "high time" there was an investigation.

In a joint statement, Holyrood presiding officer Ken Macintosh and chief executive Sir Paul Grice said the reports were "disturbing and deeply concerning".

They said: "The Parliament takes a zero-tolerance approach to sexual or any other form of harassment and we would strongly urge anyone who has witnessed or experienced harassment to report it to the Parliamentary authorities.

"We fully appreciate that, regardless of who you are, coming forward with allegations of this nature can be an extremely daunting, indeed traumatic, prospect.

"We have therefore instructed the parliamentary authorities to set up a dedicated, confidential phone-line to provide those directly affected or concerned about sexual harassment with a professional source of advice."

The statement also confirmed the Presiding Officer will convene an urgent meeting with party leaders at Holyrood on Tuesday.

While the number of reported cases over the lifetime of the parliament was "very low", they said it was "important that we ask ourselves whether that truly reflects the scale of the problem or simply reflects a culture where people do not feel able to come forward and report it."