JAMMU, Nov 22 — Five persons were killed and six wounded when suspected separatist guerrillas stopped a truck convoy near Banihal in the first major attack in the troubled region since New Delhi announced a ceasefire for the coming holy month of Ramzan.

The Inspector-General of Police, Mr R.V. Raju, said the militants stopped trucks late last night on a national highway running through troubled Kashmir, ordered the people out and then fired indiscriminately.

The attack occurred near Banihal, some 180 km from Jammu, the winter capital of strife-torn Jammu and Kashmir, and the victims were mostly Sikhs, the police said.

Police Deputy Inspector-General S.K. Mishra said six to eight militants, some of them dressed in Army fatigues, were involved in the attack.

‘‘The truck drivers saw the men in Army uniforms and thought it was a routine security check,’’ he said. ‘‘Once they came out, they were rounded up and shot dead.’’

Four of the dead were Sikhs, who are rarely targeted by Muslim militants. A previous attack, which coincided with a visit to India in March by US President Bill Clinton, saw militants gun down 35 Sikhs.

Two of the dead have been identified as Jagjit Singh of Baramula and Rachpaul Singh of Dhariwal (Punjab). The injured have been identified as Ranjeet Singh of Baramula, Lakhwinder Singh, Anil Kumar and Surinder Paul of Dhariwal (Punjab), Samrinjit Singh of Jagirpora, New Delhi and Mangal Kumar.

Immediately after the latest incident security was tightened along the 300-km highway connecting Jammu to Srinagar, the state’s summer capital, the police said.

No group had so far claimed responsibility, Mr Raju said.

New Delhi announced its planned ceasefire at the weekend. It is due to go into force once Ramzan begins, which this year is expected around November 28 when the new moon is sighted.

Several guerrilla groups have dismissed the ceasefire offer as a ploy to win international sympathy and have threatened to step up violence across Kashmir.

Jammu and Kashmir Minister for Home Affairs Mushtaq Ahmed Lone, said he believed the attack was linked to New Delhi’s surprise ceasefire offer.

‘‘There is no other occasion for this, except that it is connected with the ceasefire,’’ he said.

Meanwhile, militants gunned down three persons, including two activists of the ruling National Conference (NC), and triggered an explosion outside the house of another political activist in Kashmir today.

The Governor, Mr Girish Chandra Saxena, the Chief Minister, Dr Farooq Abdullah, and the minister for Transport and Information, Mr Ajatshatru Singh, have condemned the gruesome killing of truckers by militants on the Jammu-Srinagar national highway last night.

In a message, the Governor described it as a senseless act of the enemies of peace and said the killing of innocents had shaken the conscience of people. He said all right thinking people would condemn the barbaric act of militants.

Condemning the incidents, the Chief Minister in a message said the killing of innocents was an act by militants to terrorise people and create ill-will between various sections of society.

Dr Abdullah conveyed his deepest condolences to the bereaved families saying that they should not feel alone at this hour of grief. “Each one of us share their agony”, the Chief Minister said the instructed the police to nab the killers immediately.