"ISAF can confirm that four explosions, believed to be rockets, occurred in the environs of Kabul," between 11:00pm (18:30 GMT) Sunday and 2:00am Monday, the peacekeeping International Security Assistance Force (ISAF) said on Monday.

There were no casualties and troops were investigating the explosions in northern Kabul, which follow an attack last week in which three rockets hit the city, but hurt no-one.
 
Deputy Interior Minister General Hillal al-Din Hillal said one rocket damaged a house in northern Kabul, but there were no injuries.

The rocket punched through the roof of a house three kilometres from the Loya Jirga "grand assembly" site in west Kabul where about 502 delegates were debating the draft constitution.

A Taliban spokesman claimed responsibility for the attack and an assault on Saturday night on a border post near the southern town of Spin Boldak, in which at least five Afghan soldiers were killed and three wounded.

"We claim responsibility for the rocket attack last night in Kabul and the Spin Boldak attack," said the spokesman who called himself Abd al-Samad.

Delegates threatened

Abd al-Samad warned of further attacks to disrupt the Loya Jirga, expected to ratify the draft constitution which will pave the way for presidential elections scheduled for June 2004.

Taliban fighters have become
more active around the capital

"There are still more attacks to come," he said. Police have seized at least 94 rockets around Kabul over the past week.
 
Security forces are already on high alert with thousands of Afghan soldiers, ISAF peacekeepers, US troops, Afghan police and secret service agents providing layers of security for the Loya Jirga where debate was continuing on the constitution.

Differences remain over the extent of presidential control and the balance of power between the central government and the provinces, but senior figures at the Loya Jirga said they hoped for a consensus.

Karzai ultimatum
 
President Hamid Karzai at the weekend repeated he would only stand in the elections if the Loya Jirga approves the presidential system proposed in the draft.

The delegates, who include 100 women, have been divided into 10 groups to discuss key issues which are due to be completed on Monday before open sessions begin to ratify the controversial document.

Opened last Sunday by former monarch Muhammad Zahir Shah, the Loya Jirga is expected to finish by Thursday.
 
Several of the delegates, including some powerful Soviet-era mujahidin, have said they would prefer a prime minister or at least a parliament with real teeth to counterbalance sweeping presidential powers.
 
But with Afghanistan slowly emerging from decades of conflict, delegates appeared to have backed Karzai's view that a strong presidential system is needed as the country lacks mature political parties for a successful parliamentary democracy.