Manal al-Sharif on the road in Saudi Arabia YouTube

A Saudi Arabian woman who was jailed for driving a car has been released after nine days, having pledged to take no further part in a campaign to persuade the Saudi authorities to allow women to drive.

Manal al-Sharif, 32, was freed from the women's prison in Dammam on Monday. She was arrested after posting a video of herself driving around the eastern city of Khobar as part of the Women2Drive campaign of which she was a key organiser.

Her case attracted international attention after her lawyer said she had been charged with driving without a licence, prompting other women to do the same and provoking public debate in Saudi Arabia. Two other women associated with the campaign were also questioned by police and warned off further campaigning. One Muslim cleric even called for Sharif to be lashed.

"She wrote a pledge that she will not drive a car and after what has happened she has decided to give up the campaign and not be part of the protests," said Sharif's lawyer, Adnan al-Salah.

He said the authorities had not imposed the conditions, but Sharif had decided to make the pledge herself.

The climax of the Women2Drive campaign, a mass drive on 17 June partly inspired by demonstrations against restrictions on civil liberties across the Middle East, now appears to be in doubt.

On Tuesday, Sharif expressed "profound gratitude" to King Abdullah for ordering her release and appeared to abandon her call for women to be allowed to drive, according to a written statement published by the al-Hayat newspaper.

"Concerning the topic of women's driving, I will leave it up to our leader in whose discretion I entirely trust, to weigh the pros and cons and reach a decision that will take into consideration the best interests of the people, while also being pleasing to Allah, and in line with divine law," she said, according to a translation of her statement.

"On this happy occasion, I would also like to affirm that never in my life had I been anything beside a Muslim, Saudi woman who aspires to remain in God's good graces and to safeguard the reputation of our beloved country."

Wajeha al-Huwaider, a women's rights campaigner and friend of Sharif, who videoed her as she drove around and was herself questioned by police last week, said she was certain Sharif was told to drop the issue as a condition of her release.

"Usually when they are released, they are warned not to get in touch with anybody, not to talk to the media and not to get involved in any activity," she said.

"I am sure they told her we shouldn't continue with this issue. They told me that and the message was clear to me. I am sure for her it was even stronger."

Sharif's phone was switched off on Tuesday. A colleague at Aramco, the Saudi oil company where Sharif works as an IT security expert, told the Guardian he believed she had been warned off speaking out.

Huwaider praised Sharif, saying that whatever her ongoing role in the campaign "she represents another woman hero who tried in her own way to improve the situation of women".

"She succeeded in sending a message all over the world and educating people in Saudi Arabia about the need for ordinary Saudi women to drive," she said. "We will continue the fight, but we will use different ways."

In her statement, Sharif was also critical of elements in Saudi society which had attacked her driving protest as immoral and irreligious.

"I was stunned to learn of the accusations hurled at my religious and moral beliefs especially that they originated from individuals I least expected to go down that route," she said.

"I held my breath for those speaking in the name of religion and others. May Allah guide them rightly to do me some justice, and that if I had done wrong to blame me only accordingly and fairly, without defaming my faith, creed, and moral system."