Libya’s political strife intensified on Monday as a rival government that has seized the capital stepped up its battle for power and legitimacy, taking control of a key oilfield, according to a security commander, and meeting its first foreign minister.

An armed brigade from Operation Dawn, one of the factions backing the rival government, took control of Libya’s largest oilfield, El Sharara, a commander in charge of security at the site said. If confirmed, it would be the first attempt to take physical control of oil production by the rival government.

The Tripoli-based rival administration has also appointed its own oil minister in a move seen by analysts as designed to assert more pressure on Libya’s National Oil Corp, which had previously remained largely above the political forces tearing at the seams of the country. […]