The International Criminal Court (ICC) said on Tuesday it would give Libya more time to say whether Saif al-Islam Gaddafi, the most prominent son of the country's former leader, will be surrendered to face trial for war crimes.

The Hague-based global court has issued an arrest warrant for Saif al-Islam, after prosecutors accused him and others of involvement in the killing of protesters during the revolt that eventually toppled his father, Muammar Gaddafi, in August.

But when militia fighters captured Saif al-Islam in November, Libya said it wanted to try him at home.

The ICC had earlier given Libya a Jan 10. deadline to confirm whether and when it would surrender Saif al-Islam and to give information about his mental and physical health.

It also wanted Libya to answer concerns, raised by activists, that Saif al-Islam was being held incommunicado, without access to lawyers.

Libya had asked for a three-week extension, citing security concerns, but the court on Tuesday said it needed the information in two weeks, by January 23, because it wanted to avoid a delay in proceedings.

Last month, Human Rights Watch urged the Libyan authorities to allow Saif al-Islam immediate access to a lawyer to help ensure he has due process.

We consider it positive that Libya is engaging with the ICC and following the procedures. At the same time, we're worried that security considerations will be used to justify undue delays in the case, Fred Abrahams of Human Rights Watch said on Tuesday.

Security is an issue, and the government doesn't have full control of the country, but that should not be used to unduly slow the process. In the meantime, Saif should be granted immediate access to a lawyer, added Abrahams, who visited Saif al-Islam in December.

Saif al-Islam would rank among the biggest names to go before the ICC if he were transferred to The Hague for trial.

The ICC had also issued arrest warrants for Muammar Gaddafi and Libya's former intelligence chief Abdullah al-Senussi. The elder Gaddafi was killed shortly after being captured alive by fighters who abused him.

Last month former Ivory Coast President Laurent Gbagbo appeared at the court to face charges of crimes against humanity, the first former head of state expected to be tried by the court since it was created in 2002.

(Reporting by Sara Webb; Editing by Alessandra Rizzo)