Kabul - A would-be suicide bomber who was trying to target a US military convoy in Kabul was arrested by Afghan security forces, while seven Taliban militants were killed in two separate incidents in the southern region, officials said Thursday.

The would-be bomber was arrested in the Company area, located on western outskirts of Kabul city, on Wednesday as he was trying to target a convoy of US military forces which was passing by the area, the Interior Ministry said in a statement.

The man was driving a Toyota Surf vehicle, loaded with 170 kilograms of explosive, two cylinders filled with ten kilograms of gas and three litres of petrol, the statement said.

The militants have increased their activities in Kabul city, the main seat of power of the Western-backed Afghan government.

The arrest came a week after eight suicide bombers attacked three government buildings in the city, killing at least 26 people and wounding over 50 others.

Meanwhile, three militants were killed in Kajaki district of the southern province of Helmand on Wednesday when a bomb they were trying to plant on a road in the district exploded prematurely, an Interior Ministry statement said.

Separately, four insurgents were killed in a fight with Afghan army forces in Panjwayee district of the southern province of Kandahar on Wednesday, the Defence Ministry said in a statement.

Army forces seized ten tractors that Taliban insurgents had stolen from local villagers in the province, it said, adding that the militants were using the tractors to dig tunnels and build military fortifications.

The Taliban-led insurgency is on the rise as the weather in southern and eastern regions of the country warms.

US President Barack Obama has announced the deployment of 17,000 extra soldiers to Afghanistan this year. With the new forces, the US will have more than 50,000 troops by summer, while over 30,000 other soldiers, deployed from 40 nations, are also stationed in the war-shattered country. (dpa)