Srinagar: Militants on Tuesday carried out four attacks targeting security personnel in as many hours in the Kashmir Valley, injuring three CRPF jawans and a policeman.

Two grenade were lobbed on security installations in central Srinagar in a span of about five minutes followed by an aborted attempt to target a police party with a grenade in south Kashmir's Shopian district. Later a policeman was shot at and injured in nearby Anantnag district, prompting authorities to tighten vigil.

No militant outfit has claimed responsibility for the attacks which come barely four days after Chief Minister Omar Abdullah announced plans to revoke Armed Forces Special Powers Act from certain parts of the state.

The first incident occurred at Maisuma area near Lal Chowk when the ultras hurled a grenade targeting a CRFF bunker outside Dashnami Akhara building at 12:25 PM, official sources said.

The grenade exploded resulting in injuries to three CRPF jawans who were admitted to a hospital.

Minutes later, another grenade was hurled by militants at a police post in Batmaloo, less than a kilometre away from site of the first blast, the sources said. No one was injured in the Batmaloo blast.

Police and CRPF personnel cordoned off both the sites and detained a suspect for questioning.

As the security agencies were looking for clues to identify and nab the attackers behind the twin grenade attacks, militants made another attempt to target policemen in Shopian district of south Kashmir.

Militants threw a grenade at police personnel who were on guard duty outside a bank, in Zainapora area, 55 kms from here, at around 1435 hrs, the sources said. No one was hurt as the grenade did not explode, the sources said, adding the bomb disposal squad later neutralized the grenade.

In the fourth strike, suspected militants shot at and injured a policeman in south Kashmir's Anantnag district.

Constable Anzar Mugloo was on patrol duty when he was shot in the abdomen by militants from point blank range in the main market of Anantang town, 55 kms from here, a police official said.

He said Mugloo was immediately shifted to a hospital.

Militants this year have suffered major set-backs as security forces eliminated some of the most wanted commanders of different outfits including Lashker-e-Toiba and Hizbul Mujahideen.

The latest strike by militants come less than a fortnight after gunmen shot dead a policeman outside Hazratbal shrine, on the outskirts of Srinagar.

Constable Sajjad Ahmad was shot in the head by militants while he was on duty on October 14. He succumbed to injuries a day later.

Earlier on September 28, militants killed a policeman at crowded Batmaloo bus stand in the city.