Two more massacres are reported to have taken place in Algeria, bringing to nearly 40 the number of people killed by suspected Islamic militants in the past day.

Fifteen travellers were killed west of the capital Algiers when an armed group opened fire on a bus, and five people were killed in a separate incident one hour later, local sources told the French news agency.

This follows the killing of 15 students and their supervisor in their dormitory overnight on Saturday.

Altogether nearly 150 people have been killed so far during the Muslim holy month of Ramadan, when Islamic fundamentalist rebels traditionally step up their attacks.

Most of those killed have been civilians or members of the security forces.

There have been three attacks in the past 24 hours:

• Fifteen travellers reported killed at Tenes, 200 km (130 miles) west of Algiers

• Five people killed, including three women, at Khemis Miliana, 120 km west of the capital

• 15 students and their supervisor killed in an overnight attack at a boarding school in Medea, 80 km south of Algiers

In this first incident, gunmen burst into a dormitory while the students were either asleep or reading and opened fire. The students were all aged between 15 and 17.

No one has yet said that they carried out the attack, but witnesses said the attackers were Islamic fundamentalists belonging to the Armed Islamic Group (GIA), believed to be the most active armed group in the area.

Army crackdown

The area around Medea was the scene of violence earlier this week, when up to 12 Algerian soldiers killed in an ambush on Wednesday at Ksar El-Boukhari.

Algerian press reports said on Sunday that security forces had used air-to-ground missiles fired from helicopters to kill 18 armed Islamic extremists in a major operation between Tuesday and Thursday of last week.

The security forces launched the attack in the Jijel region, east of Algiers, after extremists killed nine communal guards in an ambush in the same region.

The El-Youm newspaper said the extremists killed in the operation had belonged to a group known as the Salafist Group for Preaching and Combat (GSPC), which has rejected President Abdelaziz Bouteflika's moves towards national reconciliation.

Amnesty

Mr Bouteflika offered a limited six-month amnesty to armed groups in July 1999, which led about 1,500 militants to turn themselves in.

He has ordered the security forces to crack down on those who failed to take up the amnesty.

More than 100,000 people have died in the violence which has plagued Algeria since 1992, when the army called off the second round of elections which the Islamic Salvation Front was set to win.