A truck pulled down 70 metres of overhead wires in Clifton Hill on Sunday morning, causing commuter chaos amid a weekend of road closures and road works.

At 6am the truck went under the Clifton Hill bridge and then struck the wires, halting the Mernda and Hurstbridge train lines.

Buses replaced trains on the Mernda line between Parliament and Bell Street and between Parliament and Heidelberg. A train shuttle service was also operating between Heidelberg and Hurstbridge.

By 11.40am, trains were running again on the Mernda line between Clifton Hill and Bell and the 86 tram resumed.

Hurstbridge line services resumed between Clifton Hill and Heidelberg at midday with minor delays.