Indian solders have killed a Pakistani soldier who had strayed onto their side of the de facto border in the Kashmir region, officials from both countries say.

An AK47 rifle was found alongside the body of the soldier, according to Lieutenant-Colonel Rajesh Kalia, a spokesman for the Indian army's northern command.

"We detected some suspicious movement yesterday near the LoC (Line of Control) inside our territory and the challengers from our side fired and in the ensuing firefight he was killed," he told AFP news agency on Friday.

A Pakistani security official said contact was being made with the Indian authorities for the return of the body of the soldier, identified only as Ikhlaq.

The soldier had been killed on Thursday night after he "inadvertently crossed the Line of Control in Khoi Ratta sector", the Pakistani official told AFP on condition of anonymity.

Curfew re-introduced

News of the Pakistani soldier's death came as Indian authorities re-introduced on Friday a strict curfew across most of Indian-administered Kashmir, amid simmering anger over the secret execution of a Kashmiri man last Saturday.

The northern state was rocked by violent anti-India protests after Mohammed Afzal Guru was hanged in a New Delhi jail and buried there. Guru had been convicted for his role in a deadly 2001 attack on India's parliament that killed 14 including five assailants.

Many in Kashmir believe Guru did not get a fair trial and the secrecy with which the execution was carried out only stirred anger in a region where anti-India sentiment runs deep.

A curfew has been in place since the execution, but groups of demonstrators have defied it and clashed with government forces. Three protesters have been killed and more than 100 have been detained, according to police.

Return of strict curfew

The curfew was relaxed in some areas in recent days, but was restored before Friday prayers in Muslim-majority Kashmir.

Early Friday morning, police drove through the streets of Srinagar, the region's main city, ordering residents to stay indoors.

The return of the strict curfew comes as the All Parties Hurriyat Conference, an umbrella organisation of separatist political and religious groups, called for a mass funeral prayer for Guru to be held on Friday at a large square near Srinagar's Martyrs' Graveyard, where hundreds of separatists and civilians killed in the region's long-running conflict are buried.

Armed Muslim groups have been fighting Indian security forces in Kashmir for more than two decades, demanding either a separate state or merger with Pakistan.

The region is divided between India and Pakistan and claimed in its entirety by both.