COTABATO CITY, Philippines -- Unidentified men tossed an explosive at the residence of Maguindanao Representative Didagen Dilangalen here Sunday night.

Citing initial reports, Chief Insp. Willie Kasuyo, city police spokesperson, said no one was injured in the 6 p.m. blast.

The explosion left a three-foot hole at the fence of Dilangalen's residence in Shariff Kabunsuan district, Barangay Rosary Heights 3.

Elements of the Scene of the Crime Operatives (SOCO) were still determining the make of the explosives as of Sunday night.

It was not known whether Congressman Dilangalen was in his home during the blast.

Witnesses told the police that the blast could have been caused by a hand grenade thrown from outside of the residence because something hard landed in the compound followed by a loud explosion.

Small variety stores across Dilangalen's residence were also damaged.

"The ground trembled, a very loud explosion was followed by thick black smoke," a witness said in a radio interview.

Other witnesses said that shortly before the explosion, a motorcycle with two men on board was seen speeding away.

Police could not say whether the grenade attack was election-related since Dilangalen had filed his candidacy for reelection and his wife has also filed her candidacy papers for mayor of the city.

No one has claimed responsibility for the attack.